I used the Netduino previously. Worked quite well and was easy to program using VS and the .Net Micro Framework.
One of my projects was replacing the microcontroller on this automatic cat litter box. I renamed it the "TurdMaster 2000".
The original problem was that my cats don't quite uhm, cover up when they are done, and the original design called for the feline to cover up before leaving the litter box. It would then sit for 7 minutes until the product was "baked" and then go into its roll action that would dump it out at the bottom.
My updated design changed it from Bake 'n Roll to Shake, Bake 'n Roll, which resolved the design flaw in my case. So after sensing the cat has left, it would go into a Shake mode where it would perform a few roll motions so that said product gets covered up, then lets it Bake for the required 7 minutes before dumping out.
Unfortunately one of the cats never got used to the noise it made and ultimately I had to get rid of it. Pity as I was rather fond of the TurdMaster 2000 after all the time and effort I put into it...