The wireless deaddrop project was the solution that i was able to create for the least amount of money. There are many routers that will do this a bit easier but they cost at minimum $150.
Why a Deaddrop?
The name comes from the old spy technique of sharing files, from wikipedia:
"A dead drop or dead letter box is a method of espionage tradecraft used to pass items between two individuals using a secret location and thus does not require them to meet directly. Using a dead drop permits a case officer and agent to exchange objects and information while maintaining operational security. The method stands in contrast to the live drop, so called because two persons meet to exchange items or information."
Deaddrop style projects seek to take information and files out of the general internet stream and make them available in a way that requires going to a physical location. This sort of file sharing is much more personable than just grabbing files from the internet. It is also a good way to share sensitive files as it can be obscured and even utilize encryption.
WARNING: This project involves flashing a router, which could break said router, and give you emotional hardship and having to learn how to telnet into a router. (FUN!) I'm not responsible for breaking your router or that you might gain experience on the linux command line that may be totally useless.