Ok, I just finished building my desktop, already running windows 2000 on it (bought ms office 2000, paintshop pro 7, plus many other semi-expensive apps and I'm going to use them...). But I still ...

In technical terms, DeltaCopy is a "Windows Friendly" wrapper around the Rsync program, currently maintained by Wayne Davison. "rsync" is primarily designed for Unix/Linux/BSD systems.