I've traveled for free in many countries using a variety of different strategies. Traveling for free does not mean starving, begging or skimping. You can travel for free in style. This blog tells you how.
I haven't personally applied and it is potentially only US based but probably something worth of consideration for anyone with a lot of connections, friends, fans or followers. If you can't pull a full group together as outlined in the initial posts on the blog - then here is a good fallback that still earns you some cash so you can travel for free.