This project inspired by http://www.claytonfelt.com/peavey-vypyr-vip-amp-diy-midi-footswitch/ and http://zorkmids.com/?p=1425 This footswitch controller is a very simple controller, both in logic and use.
The basic idea is you have 1 or more footswitches. Let's say two for this discussion. The first footswitch changes between preset 0 and 1, and the second footswitch changes between preset 2 and 3. The important part here is, it remembers what each switch was at, so if you click switch 1 and then switch 2, then switch 1 again, the state will be whatever switch 1 was set to previously. This just makes sense to me. Maybe not to you.