Distributed File Sharing

How do you do it? My company has offices all over the US, UK, and Europe. I'm sure we'll have an asia office or 3 pretty quick here. so what do we do about keeping everyone on the same page? Distributed email, services, phones - no problem. The options I see:

everyone uses one file share
+ central management and easy admin
+ everyone knows where stuff lives
-slows down the further away you get
- maybe some security risks with everyone in the same pot
- big by


syncronized file shares
- pain to do
+ best solution for end users


This is gonna be fun.