iChalky

* Selected by O'Reilly Media as a Best iPhone App, and featured in O'Reilly's upcoming book, "Best iPhone Apps: A Guide for Discriminating Downloaders"

* Voted "Best Kid Distraction App" from the 2008 Best App Ever Awards

************** NEWS ************* Announcing the first release of SPARTICLE, an iPhone / iPod Touch game that takes iChalky's physics to the next level. Visit www.metois.com/Sparticle for more information. **********************************

Chalky is a stand up guy, or at least he tries very hard to be.

Chalky is a simplistic stick figure whose posture and behavior result from the mechanical constraints that define him. He consists of a set of 8 masses connected to one another through a series of damped springs with various coefficients. Gravity and instantaneous acceleration are estimated from your iPhone's X and Y accelerometers and transferred onto Chalky's virtual world.

Friction was further added to the edges of his frame along with some rudimentary stepping heuristics to give him a fighting chance to maintain his balance as you rotate your phone around or take him on the bus with you. You can also grab, stretch and throw him with your multi-touch screen if you feel he's not getting enough abuse.

Chalky also thinks he can dance and he'll start busting his moves if he detects music through your phone's microphone... so crank up the tunes! Unfortunately you can't use the iPod application on your phone as I couldn't figure out how to make that work.

Chalky is not artificially intelligent and none of his gestures are choreographed. He illustrates the fact that humble perceptual measurements and simple constraints set in a physically meaningful environment can lead to interesting and sometime unexpected behavior.

A video demonstration is available on iChalky's website.

NOTE: This application monitors your microphone audio input. In order for Chalky to dance you must be using either an iPhone or a 2nd generation iPod Touch with a set of headphones that include a microphone. Contrary to some reviews iChalky works on any iPod Touch.