Check out this super fun officially licenced dancing baby groot USB charger from Thinkgeek:

Have your phone charge to the cutest little floral colossus this side of the galaxy. The Marvel Groot USB Car Charger features the little guy in his tiny pot dancing around while he charges your phone or any other compatible device. Groot will stay nice and safe inside your cup holder, so, luckily, he won’t need to make the ultimate sacrifice just so your phone doesn’t die.

[Marvel Groot USB Car Charger]