Hi there guys!! I thin what you whant to do is the same as I do. Basically you want a system just like Dropbox but instead of syncronize the files to a server outside your house you want it within your personal network, so that anytime you make a change on one of the folders (if you're conected to the network) it will automatically sync only the changes (instead of copying the whole folder every time) wich reveals itself much more time and patience saving!
Well I've been trying some programs betweenmy 2,0Ghz C2D MacBook Aluminum with Mac OS X 10.6.2 Snow Leopard and my 400MHz G3 Graphite iMac (but with a 120 Gb HD) with Mac OS X 10.4.11 Tiger (EHEHEHEH)well if some have some ideaplease post it!! I'll keep on trying.
The only thing I can suggest you now is an app called Synk (v. 6 for Mac OS X 10.4 (Tiger) and above or 5.2.4 for 10.3(Panther) or under)
Synk v.5
Synk v.6
I haven't tried this one yep but what I've heard was that on v.6 the backup package (minimum one) is free for students. But it is an unconfirmed information so look a little bit further on that subject if you're interested
Huggs