Wow, I really like this idea!

I think, even for those of us who already got their Peachy or will get a version without this idea (yes, I'm already assuming they will use it) this is a perfect DIY-addition to the Peachy!
They could easily provide a pin or two from the Peachy board and write a software version that uses the new sensor.
I like the idea that you can just make the tape on the outside bigger for more movement.

According to this:
http://www.nessengr.com/techdata/liq...dresistor.html
the saline will probably have a resistance around 10-100 Ohm/cm so if you use like 10kOhms for measuring the capacity you won't see a large change.

Greetings,
quertz