Stripe Snoop, a Track 2 magstripe decoder has been released into the GPL, and is available in source or binary from at my homepage, Most Sigificant Bit.

Included is a detailed article about interfacing Magstripes to PCs, diagrams and pictures, as well as the software itself.

I will be presenting a talk about Magstripe interfacing at Intersz0ne III this weekend

.. and, I built a coke machine that works