Why yes!
In the terminal, you can restart the finder:
killall -HUP Finder
This will send the unix "hangup" command to the finder, which means it'll quit and start again. This alone could fix your problem, but if not:
you can unmount the ipod before you restart:
sudo umount "/Volumes/iPod Name"
(of course, replace iPod Name with the name of your iPod drive)
I recommend trying to restart the finder first. You won't lose information on your iPod this way (unless its partway through copying a file, in which case you'll only get part of the file on the iPod).