I'm currently in college, and we work in groups of three to create small python projects on a weekly basis.
We code with Eclipse and PyDev but we've got a problem when it comes to sharing our work. We end up sending an infinite stream of emails with compressed projects.
What we need is a way to keep the source code updated and we need to be able to share it between us. (on both Windows and Linux) What do you recommend? 
thanks in advance.
I'd suggest using a version control system.
Git might be good for you - it doesn't require a central server and there is also support for Windows these days.
Code sharing between small student group