How to Travel Around the World as Inexpensively as Possible
I suppose that the cheapest way to travel around the world is to walk around a globe.
For those of you who seriously want to travel around the world but are limited on funds, please review the Around the world on low-cost thread.
There is even a link within that thread about how one can travel around the world for fewer than £500, which is roughly equivalent to US$1,000.
However, do not expect luxury. Consider yourself warned.