If you use ZENworks, this is a nifty tool for you to offer your users: USB Drive Letter tool.
It enables users to select an unused drive letter. I put the tool in the Public directory on my server and then put an application object in the application launcher.
Here's what the tool was created for:
"Getting USB Devices to work under Windows XP" USB devices can give some problems in combination with NetWare mappings. Our restricted users cannot use diskmanager to change drive letters. Therefore, I created a small tool so restricted users can change the drive letter of their USB device.
Disclaimer: As with everything else at Cool Solutions, this content is definitely not supported by Novell (so don't even think of calling Support if you try something and it blows up).
It was contributed by a community member and is published "as is." It seems to have worked for at least one person, and might work for you. But please be sure to test, test, test before you do anything drastic with it.