Had to copy a lot of data (10 gig) between two Windows machines today. Simply copy and pasting the files didn't work because Windows would get one file that was in use and stop the whole proceedure. DOS' copy command wasn't much better, having only 5 options.

xcopy was up to the task. Xcopy has a lot of really cool and useful options for copying a lot of files. It's no rsync, but it's a pretty decent util (at least compared to the alternatives) to copy data.