FlashDealer.com offers personalized technology items for a low price. And they are not limited to plastic either! You can choose from wood, leather, aluminium and so on. You can even have USB sticks in all kind of funny shapes.
Personalized USB Drive is a great gift for the geek in your life, but it will be appreciated by non-geeks also. And if you think that they won't find a use for it (even for the ones which look like bracelets :-)), you can always go with an MP3 player.
After doing some due-diligence (like searching around for complaints related to the company and looking since when they are in operation, they seem to be a good source to order these gadgets from. One word of caution though: they offer multiple brands of flash drives for customization. I would recommend choosing a more well-know brand, rather than going with the cheapest option. I'm saying this because I saw that one type of MP3 player they offer for sale is very similar to Canyon one I bought many years ago when I was still a student (because back than it was the cheapest option). It had problems from the start (like the previous-next rocker switch not working properly) and it didn't last more than a year (not that all Canyon products are necessarily unreliable - since then I've had two Canyon routers - one wired and one wireless - and both work perfectly to this day). The moral of the story is that you should go with well-known brands to avoid the hassle.
Finally, if you do decide to buy a USB storage device (either for yourself or as a gift), make sure that you "vaccinate" it against autorun worms and read up on the encryption options available for USB drives, since (due to their small size and mobility) they are in constant danger of being lost with all the data on them.
Full disclosure: this is a paid review from ReviewMe. Under the terms of the understanding I was not obligated to skew my viewpoint in any way (ie. only post positive facts).