I've used grsync just on my local lan and found it pretty easy to
use. It can even run a custom script both before and after you run
your backup.
I'm sure it works just fine with DSU. Note that if you don't want
Grsync to open up a command prompt, asking for your ssh password each
time, don't forget to generate and then upload an rsa key to the dsu
server. The first time I ran Grsync, I thought it had locked up on me
when in reality it was waiting for me to type in my password in a
separate window (which I didn't see b/c it got buried behind 10 other
windows).
If you try Grsync and get stuck, feel free to post any specific
questions you have. I'm sure someone here would be able get you
going.