Makes me giggle when I remember Joel's rant (http://www.joelonsoftware.com/items/2008/05/01.html):

"Since 1988 many prominent architecture astronauts have been convinced that the biggest problem to solve is synchronization.

[...]

When did the first sync web sites start coming out? 1999? There were a million versions. xdrive, mydrive, idrive, youdrive, wealldrive for ice cream. Nobody cared then and nobody cares now, because synchronizing files is just not a killer application. I'm sorry. It seems like it should be. But it's not.

[...]

this so called synchronization problem is just not an actual problem, it's a fun programming exercise that you're doing because it's just hard enough to be interesting but not so hard that you can't figure it out."

You show him!