I was looking to order one of the GelaSkins (gelaskins.com) iPod art skins, but I was wondering if anyone has any experience or opinion on them? I already have my iPod in a clear plastic shell and thought it'd be cool to display the GelaSkin artwork through the shell on the back. However, I don't want it to be permanent or leave any sort of residue or anything as I'm looking to eventually sell my iPod for an iPhone.. so.. anyone here with any first hand experience with them?