Normally a toothbrush isn't a gadget but this one has an electrostatic charger and a USB charging travel case. It has a built in timer so you brush for the correct amount of time and has a few different modes.
I've always had an issue keeping my teeth white since I smoke and drink coffee. After two weeks of using this toothbrush I've seen a huge difference and think it's worth spreading the word. If you are serious about dental hygiene this is a must for Xmas.