Swedish designer Peter Thuvander likes yo-yo's so much that he designed an iPhone charger concept around them. Called the iYo (what else?), the device charges its lithium ion battery cell with an OLPC crank that's turned using the spinning power of a yo-yo. "The remote control needs only 30 cranks—which is nothing when you yo-yo," he said. Just 30 cranks and your dignity, Peter. I kid, of course, being someone who sleeps with a Duncan yo-yo under his pillow. The video demonstrates what a good idea this is:

[Peter Thuvander via Core77 via Treehugger]