I as talking to a few colleagues at the IA Salon about some new ways to use hardware/software to control audio -- applications that mix tactile physical interfaces with digital audio.

FinalScratch is commercial software and hardware (cable interfaces and special records) that work with turntables to allow a DJ to play and scrub (move back and forth) through MP3s on the computer. A video on TechTV shows how it all works.

Audiopad is a remarkable project at MIT that uses a projected image interface (a la Minority Report) and a physical widget that looks something like a plastic disk to select and control play of audio tracks and use filters against them. The video is truly amazing.