You've probably seen these

Toothbrush-
http://www.watch.impress.co.jp/akiba..._habrashi.html

Coffee warmer
http://www.sunbeamtech.com/PRODUCTS/...%20WARMER.HTML

Not usb but odd - air cooled jock strap
http://www.gizmodo.com/gadgets/image...04008%2C00.jpg

USB razor
http://www.engadget.com/entry/1234000473054105/

Wouldn't chance looking at this one at work
www.blowfish.com/catalog/toys/alt_vibrators.html

Lava lamp
http://www.boingboing.net/2005/06/24...mini_lava.html

Xmas Tree
http://www.thinkgeek.com/clearance/6e2c/

Aquarium
http://www.thinkgeek.com/gadgets/electronic/6984/

Binary Clock
http://www.thinkgeek.com/cubegoodies/lights/59e0/
I've seen a binary wrist watch which looked kinda cool but was in reality completely useless.

Lost more out there.