iScratch by Shosei Oishi (a student of IAMAS Japan) is software which enables you to scratch audio files like analog record using iPod's touch wheel. Shosei re-wrote the pre-installed open source audio play program of Pozilla to be able to scratch audio files, and works using Linux.
Shosei is also a member of the Breadboard Band:
The Breadboard Band is a performing band that uses breadboards made of freely constructed electronic circuits to play music. We produce audio and visual expression through the most minimal, fundamental elements in the form of showing the electronic components of an instrument while directly touching and forming the electronic circuit by hand. The electric signals released from hand-made electronic circuits releases extremely rough and ferocious wave patterns. This performance is based on improvisational interplay, and we pull powerful music into shape through each member's operation, while discovering new sounds by hand.