A few days ago I came to know about Summer of Code a google program, an effort by google to introduce students to world of open source. The list of projects in it is very good & extensive. A very interesting project that was done as a part of it is TSync. It is described as “a time-saving convenience that allows you to save the file on one device and have it updated automatically on other PCs, laptops, personal digital assistants or even third-generation cell phones.“Go read about it here.
I think it is incredibly cool and would have terrific ramifications in our technology lives.
Btw here are some existing sync companies/technologies
mtrajan.com 
google talks about open source !!!
hmm … will they release any code for their BETA’s š
The code of TSync is GPLed and already available for download.
http://tsyncd.sourceforge.net/