Just received two kblites (http://www.kbcovers.com/servlet/Detail?no=235) in the mail from kbcovers (who do keyboard overlays, including one for traktor) and I have to say, they're amazing.

Before I bought these I tried my luck with some cheapies on ebay, but they were just what they were - cheap - rubbish.

The kblites seem pretty pricey, but they're the best usb lights I've even seen. I'd personally like to see DJTT stock them, they deserve it.