Very Long Distance Walking
As I was packing up my tent one morning, about 100km away from Cusco, in the middle of nowhere, a rather odd man appeared. He was dressed in shorts and a bright red Peruvian Fire Brigade jumper. He had attached to his tiny backpack a huge Union Jack. I asked him where he had walked from. Mexico, he replied. How long did it take you? I wondered. Three and a half years. He had bits of car tyre glued to the bottom of his boots. He didn't carry a sleeping bag.
I think it is fair to say that walking is just about the slowest form of land transport. I can see a few advantages though. You are not stuck to roads, you can go just about anywhere, over mountain passes and through fields and forests. There is little to go wrong; the only thing to break is you. On the downside you can't take as much stuff and crucially you can't free-wheel down hills.
Other googlable or wikipediable (very) long distance walkers are:
Hitching like many of the best things is not easily pinned down. It can be fun, frustrating, challenging, dangerous or very boring. It can be a great way to learn a language, meet interesting people or even a dive-in-at-the-deep-end way to learn to drive. It is generally either free or low-cost, so in my mind that makes it better than buses. Jack Kerouac wrote a classic about it in On The Road. Douglas Adams broadened the scope a bit more in Hitchhikers Guide to the Galaxy. Tony Hawks hitched round Ireland with a fridge. In the Mighty Boosh there is a weird green cockney with a giant polo mint where his eye should be.
Ah, whatever. Check out Road Junky for advice and for inspiration check out Tom.
Stowaways, Boathitching and Trainhopping
"Keep everything dark, dark clothes, dark pack, dark sleeping bag or blanket. This will make it harder to get caught by the railroad cops as you blunder around the train yards."
That is the sort of terrific advice you get from Wes Modes on his website that makes for thrilling reading. He also encourages Urban Adventures, such as sneaking around factories for a laugh and climbing buildings. Check out his great website The Spoon.
Stowing away obviously has a great history as a method of crossing oceans. And on a practical level you can see why. Once the boat has left port the captain is stuck with you. I can't see it all panning out like in Treasure Island thesedays. Starving to death on a long voyage, freezing to death in the wheel-well of a plane, or being hearded into the back of a lorry don't sound like much fun. But many desperate immigrants still resort to these measures.
Boat-hitching might be a better option. How to go about it is detailed quite well by wikitravel on this page. There are a ton of websites where you can look for people who require crew on thier yacht, such as crewseekers.net, or you could just turn up at a port and get to know people.