There's no reason to have boring tech-bits if you're a little crafty - get out your glitter, paints, beads and jewels and get creative!
Back up your data! I'm serious. If you make a mistake and destroy your stick, you'll lose anything that's on it. It's not likely that this will happen (you look clever, after all), but it's always better to be safe than sorry, right?
Put low-tack masking tape on the bits you don't want to get covered with glitter - make sure the part that actually goes into the computer is covered, and any levers that might open the stick.
Lay out your design, if you're having a specific design. If not, ignore me!
Spread white craft glue evenly over everything you want to cover on one side. Stick any gems you want on FIRST, then cover the whole thing with glitter. Shake off the excess and leave to dry for about half an hour.
Once dry, turn over and repeat. You should do half of the 'little' sides each time, so that you don't have to try and balance it like that later.
Once the second side has dried, coat the whole thing in clear nail varnish - you can use a craft varnish if you like, but I like the 'invisible' finish of the nail varnish.
Allow that to dry completely, and you're done. Go wow your friends!