Custom Midi Controllers

Hey everyone,
I Have lately been into building custom midi controllers and wanted to open a general discussion about them. I have recently been using hardware from livid instruments which I have found to be very user friendly, but expensive. I have also been getting into the teensy and have found it to be a much cheaper option, although there is some what of a learning curve due to the needed coding. Has anyone else had any experience with this. Take a moment and let everyone know some of your suggestions and tips for making your own midi controller.

Take a look at OpenDeck, open-source alternative to Livid Brain and similiar setups:

http://forum.djtechtools.com/showthread.php?t=83148

https://www.youtube.com/watch?v=3T1-x4B77nw

http://shanteacontrols.wordpress.com/