Let me present you Bisync
It’s been a looong time I’ve been looking for a good solution to synchronize my mp3 collection on multiple computers, Dropbox-style. It’s quite strange, but I’ve never found anything that pleased me, so I just coded it.
Here it is, Bisync is a bidirectional folder synchronizer with distributed history, it can handle deleted and renamed files in both folders. To know more about it, see the readme on Github: https://github.com/nicolas-van/bisync .