1st post so I'm not sure if this is quite the right place to post, but here goes.
I etched a couple of single sided Arduino boards using toner transfer. Boy was that a lot of holes to drill. I had DIP atmega328P's to use up so that was OK, but next time around a surface mount design would be nice. Perhaps there is already a good one out there.
You can get these silicone calculators on www.dx.com for $4. I might take a punt on one of these, I like the idea of a flexible keypad. Does anyone have a good idea how to connect to those conductive ink traces?