HyacGsocpi = Here's Yet another cool Google summer of code project idea - looking at the very end of the Eclipse Google Summer of Code Ideas page:
Comparing, Merging and Synchronizing directory trees of remote servers between each other or with a local replica, all over standard Eclipse APIs with replacable connection schemes. The Remote System Explorer (RSE) provides the UI framework for transparent remote system access, and while it supports comparing individual remote and local files, it does not yet have support for comparing or synchronizing whole folder hierarchies.
Eclipse Platform Team/Synchronization provides the relevant APIs, and in fact these APIs have already been used for remote synchronization in the past (for the Platform Team/Extras feature that has been retired with Eclipse 3.3). RSE is the logical successor of this much wanted feature.
It's an interesting project, bringing you in touch with Eclipse, networking as well as potentially some interesting algorithms for comparing stuff with minimal data transfer. And solving the task will make you good friend with several people just waiting for Eclipse bug 185925 getting resolved by a smart guy like you!
If you're shooting for a GSoc Project and haven't got one yet, this one might be right for you! The deadline for GSOC applications is April 7, 5:00 PM PDT /00:00 UTC April 8, 2008. The FAQ for GSOC can be found here.