iCleanup deletes .DS_Store, .Trashes and ._ files from a selected volume and optionally unmounts is. I hope some people will find it useful.
[robg adds: Though we have a few hints on removing .DS_Store files from Unix machines and CDs, we don't have a hint on removing them from Windows machines. I downloaded the app and looked at the AppleScript inside the iCleanup package. It looks relatively benign, but still, it's deleting files, so having a recent backup before running it is a good idea.]

