HogFan, when the time comes I may ask for your help in determining the best PID settings, since you seem to understand it better than me. :)
Update: I did my first smoke (heh) test last weekend. It was good and bad.
Good - The hardware worked and it was relatively easy to set up. The PID output (i.e. the blower speed) seemed reasonable. The graphing software works very nice and builds a pretty chart of the cook. :)
I have verified that the software runs on an original Droid using Android 3.7.
Bad - Program crashed a few times but worse it didn't keep any kind of a steady temperature. I started with the ball valve all the way open, which was too much, and it climbed past 300 (thermostat was set for 225). I kept closing down the valve until temperatures started to drop. When the temp got to around 225 the blower kicked in but temps kept on dropping. The blower is putting out plenty of air so I'm not sure what's going on. I fixed the crashes and I plan on trying again this weekend.
The bluetooth dongle I bought has a short range and that was annoying. I've ordered another one to try with a range (supposedly) of 50 meters.
For those that might be interested, the software can be downloaded from here: https://sourceforge.net/projects/udssupervisor/