A new crop of gadgets are harnessing the kinetic power of the yo-yo to charge everything from iPhones to flashlights. Going green has never been this much fun!

The endlessly entertaining children's fad has become something even great, the design inspiration for gadgets that let the user recharge with the flick of a wrist.

Regen Music Player: Created by designers Chris Aimone and Tomek Bartczak, this MP3 player doubles as a usable yo-yo. If you ever run out of juice just sling the player up and down 10 to 12 times and it will be fully charged.

Spin and Play MP3 Player: French designer Nicholas Cinguion created this yo-yo powered MP3 player. Conceptualized for S. Electrics and named the S.MP#3, the music player is charged by stretching the headphones, which also wrap around the player like a yo-yo string.

Pullight Dynamo: This yo-yo flashlight was designed by Sebastian Sauvage to draw it's power from the kinetic enegry harnessed by playing with the yo-yo. Not only can the cleverly named Pullight light up a dark room, it also has a USB plug to charge mobile phones and MP3 players, plus it's splash-proof.

YoYo Phone: Designed by ModeLabs, this cellphone is worn around the users neck and powered by both kinetic and solar energy. The circular display is surrounded by a keypad around the edge, making it difficult to use for texting, but a still one of the best options for cellphone users concerned about their carbon footprint.

iYo: This iPhone charger was created by Swedish designer Peter Thuvander. The charger works by building up power in small battery while the user plays with the yo-yo. An iPod or iPhone can then be plugged into the iYo and charged. Check out a video of the product here.