Hawaii, if you can get there is a beautiful place to escape for vacation, or if you fit in, forever. You will have to make peace with the natives whose land you are invading but if you decide to go native and join their cause, the warm weather and friendly people make camping out long term a real possibility.
Getting there is the challenge. You could try begging friends for frequent flier miles or find a travel agent who is cool and tell him to call you when a super cheap last minute flight opens up. Another option is to stay near a west coast airport in a town like L.A., San Fransisco, Portland, or Seattle and watch the travel sites for last minute deals and jump on them. Portland, Oregon is especially well set up for this with Camp Dignity alternative housing project being located on the airport grounds and having free Internet access, PDX airport also often has lower prices to Hawaii than the larger west coast cities.
You could sniff around large west coast marinas or post to Craigslist or sailing websites and offer to crew a sailboat for a trip that could last around a month, see Sail Away. Stowing away on a large ship is quite risky and requires packing all of the food and water needed for the whole trip as well as the danger of pest spraying and security checks.
Since you don't need much clothing or gear consider just packing a carry-on bag and keeping it ready to jump on the airplane with just some clothes, a light towel, a durable swimsuit or two, sandals, a wide brim hat, and a hammock, you could bring a light pull over jacket and a small nylon tarp since you will get used to the warm weather and want it later for cool nights and rain. For guys clean khaki trousers, a nice button down Hawaii print or white shirt, and clean sandals will let you into even the fanciest locations and events for social interaction and free food, for women ask for a nicer more formal long length but very comfortable muumuu dress and sandals.
Be sure to have a return plan or better yet your up to date return ticket in a safe place, you could have a responsible friend mail it back to you as general delivery mail for you to pick up at a specified post office or electronically sent to the airline ticket counter. Travel between islands and the mainland is not a trivial proposition if you have no money. Even natives sometimes feel trapped on "the rock".
Get to know locals and find out where people are friendly to haoles. There are neighborhoods where the people prefer not to be reminded that they are being oppressed, so be sensitive to what the Amerikans have done both economically and culturally to this proud people and let them be if they choose. Most haoles come live in Hawaii for a few years, drive up prices and then leave. Many Hawaiians can barely afford rent due to the high tourist induced prices so a white face is just a reminder of the cause of their troubles. That said, let us repeat that you will rarely find people so true and warm anywhere in the world.
Traditional housing is very expensive even in the low rent areas as the haolie boomers move there to retire or buy for investment driving prices up, and most couches are already filled by relatives and friends of the natives. Most families live together in large households. Maybe you know a rich haolie (white occupier) who will let you crash in their empty condo, but otherwise camp it out. If you are public beach camping you might be evicted if you stay beyond the permitted camping period, but this is supposed to mean being moved to a shelter, but sometimes just means you have to pack up and go. If you get into a shelter you are on the top of the list for subsidized housing. The good news is since Hawaii can't just export the homeless somewhere else they actually have to deal with the problem although they are still trying to use some New York tactics. A frequently floated idea is to begin handing out one way airplane tickets to the mainland to those homeless who want to leave.
If you get a tent and a hammock you should do fine most of the time especially if you can find a group camp or a nice bit of wilderness, just be careful when hammocking that you have control of your pack lest it be stolen. Cheap tents will blow over in the winds before a storm and if there is nothing inside even a good tent can easily blow out to sea like a kite. If you stick to the dry side of an island you can expect much less rain and big storms will often be moderated but a typhoon is a time to seek real shelter. Backpacking hostels are usually at least $50-60 a night so try [couchsurfing.com Coush Surfing] or just make some friends at the beach and see if you can camp in the yard. Use the free beach showers to clean and cool off.
For longer term see if there is a farmer in the more rural areas willing to let you throw up a shack or permit you to live in a shed. We once met a blown out Iraq war vet who survived on his small disability check by gardening and beekeeping, he traded honey to the owner for permission to stay on the small patch of land in a shed with his bicycle and small truck.
Hit the food bank  and see what they have. If you are a seasoned dumpster diver be careful, the high temperatures mean food goes bad fast. Since there are so many tourists who don't finish their plates, make friends with luau or restaurant staff and during cleanup, load up. Look for plentiful fruit trees both wild and decorative if you get hungry.
Fishing in the ocean for non-commercial purposes does not require any kind of permit. You can use a pole or a net, but don't over harvest. Fresh water, commercial, and deep sea fishing do require permits.  A spear and flashlight is another way to grab some food or bait from tide pools. Just roast up your catch on the beach using collected drift wood. If you have no cooking equipment wrap the cleaned fish in easy to find banana leaves, secure the leaves with bamboo or wood skewers(toothpicks work) and roast over your fire, if possible rub with oil and lemon and/or pepper.
The state has health care for the indigent . The state requires employers to provide health insurance for all employees.
Volunteer Legal Services Hawaii, Oahu 528-7046, Neighbor Islands 1-800-839-5200
Most beaches and shoreline to 8 feet above the high water mark to the ocean are free and public except national parks, military bases, Hanauma Bay, and private hotel properties. Even if you have no board the body surfing is very fun, especially in heavy waves during a tropical depression before a storm.
If you have swim goggles or a diving mask snorkel over the coral reefs, a sock with a small amount of corn or peas will attract beautiful fish and you can feed them, although we are told that this may be illegal and may teach aggressive and sometimes violent begging in some fish.
Take a hike to see many beautiful and sometimes secluded mountainsides, rain forests, volcanic flows, lava tubes, beaches, tidepools, and waterfalls, also ask where whales and dolphins can be seen.
A bicycle is an ideal way to get around but plan your route well, sometimes a long route may be an easy paved road which follows the beach while another involves steep mountain climbs, sometimes 1000 feet in a few miles but that also means some sweet downhills. Be careful to regularly wash down your bicycle on a nice day were it can dry off, the sea air and salty beach sand will rust it quickly otherwise. Bicycles with wheels that are twenty inches or larger are required to be registered and tagged with a fee of $15, this is supposed to be for recovery if stolen but the police have confiscated unregistered cycles in camp raids. Cycle shops are rare in many areas so plan ahead.
This Pacific tropical island chain is claimed by the United States and travel is like to any other US state, no special ID or passport check if coming from another part of Amerika. Travel time is typically about 30 days by sailboat or five hours by jet from the west coast of the US. There is the windward side of every island which is the wet side, the leeward side is much drier and is somewhat protected from storms. Since all fuel is imported it is very expensive to drive a car, learn to walk, paddle, or bike for transportation. There is a strong ocean current so if planning a boat trip between islands this must be included in the calculations or you may be lost at sea. Natives built a canoe with an outrigger for stability to row between islands, modern versions are used by boating clubs for racing and occasional travel between islands.
Since Hawaii is a massive tourist center performance art and music or hand crafted souvenirs are a good way to make some cash. Always try to dress nicely and meet tourists with a big fake smile that turns real once you have their cash, play to the happy beach bum image they imagine you to be. Use some discretion when selling wares or performing so the cops won't shut you down. Also beware of tourist trap shops, get away from the hotels and watch prices even when you need simple things like a beach mat or clothes.
Two big things threatening your stuff are humidity and bugs. Simple things like a metal hanger will rust and leave stains on your shirts, tools are also always at risk. When it gets hot and still, the termites are coming, and they swarm in huge numbers so you had better have all of your windows and screens closed. The tropical environment means that cockroaches, ants, and geckos, the cool little lizards who eat bugs and bring good luck, will also enter and live in nearly all houses, so be careful to seal all food containers. Avoid clutter anywhere in the house, and clean off all food preparation and eating surfaces like tables and dishes right away to reduce the incentive for the bugs to move in and hide out. Mosquitoes are exterminated in the urban areas but netting and/or repellent are needed once you get rural.
There is an active native resistance movement which uses frequent civil disobedience and demonstrations to protest the Amerikan occupation of their kingdom.
- Hawaii Indymedia News Center 
The Aloha Stadium on Oahu has a huge flea market . Entry is $1 per person Wed, Sat, and Sun 6am to 3pm. All the cheap junk, handcrafts, and t-shirts you need to outfit yourself after falling off the boat or plane. Also a safe place to sell your wares free from police harassment if you rent a space.
Since sugarcane fields are literally everywhere in Hawaii maybe you could make a little money making rum. Get sugar cane from a burned off and cut field that got left behind. Pulp the cane in a bowl with a minimal amount of water and pour the liquid into a large cleaned bottle. Either let the natural air yeast or special packet yeast begin to convert the sugars to alcohol. Keep a loose cap or pricked balloon on the top to prevent anything getting in, a tight cap could cause an the bottle to shatter from the pressure. Once the mix stops making bubbles, distill like we describe in Strange Brewing. Sugarcane is also a sweet snack to chew on.
It goes without saying that amazing marijuana can be obtained or grown in the fertile Hawaiian soil and climate.
Good public bus and coastal boat transportation is available on Oahu  the service on the Big Island is not so great or frequent to many areas. Maui now has a bus system that is free for the central part of the island (Kahului and Wailuku) and $1 for those wishing to go to or from the outer cities (Lahaina, Kihei, Paia/Makawao), a monthly pass is $35. There is limited service coverage and large bags and packs are forbidden on the Kauai bus system.
The $70 superferry service between islands has been discontinued pending an environmental study for the last several years and is no longer running; it was ripe for stowing away. The cheapest option is now either bumming a ride on a boat or taking a regular inter-island airline. 
There are larger commercial airports in Honolulu, Lihue, Kahului, Kona, and Hilo, although there are smaller air carriers operating from small commuter airports, but these can end up expensive unless the flight crew sneaks you aboard.
The only train line left is a tourist trap between Lahaina and Kaanapali on Maui called the sugar cane train, not worth jumping.
American occupation forces have many free memorial museums, you could also sample free local music, cultural events, historical museums, and royal properties many of which are free to visitors.
Remember that if you want to live in Hawaii to be Hawaiian and to respect their culture and land, be a resident not an occupier, you are not in the 48 states anymore. For general assistance call Aloha United Way ASK-2000, Oahu 275-2000, Neighbor Islands 1-877-275-6569,