Thanks. Pressure sensing is actually pretty simple and cheap, unless you have a really large number of inputs (like I have). I was planning to switch to a matrix layout in the next version to reduce the number of ADC chips I need, but then I'll have to figure out how to mitigate ghosting.

I haven't used any of Sensitronic's producs, but they do have a lot of good information on their site about the various ways to use force-sensitive resistors.