Fancy making your own MultiTouch interface?  Well, there's a $2 DIY way of doing it, but be warned - it's not exactly pocket friendly!  Over at Medallia they've posted this video of a rigged-up touch interface consisting of a plastic bag, water dyed blue and an Apple iSight camera.

Basically the camera - mounted underneath the bag - monitors changes in colour as you squeeze different parts of the bag and translates those into mouse actions.  From the video it looks accurate enough to hit links, and of course it can do the usual MultiTouch pan/zoom demo thanks to the tricksy software Medallia have created.

This isn't really something you'd be wanting to transport around with your MacBook, but as a proof of concept it's pretty damn cool.