I honestly didn't know how much demand there'd be for a stickduino sheild. I didn't expect the "small USB stick sized" crowd and the "shield prototyping" crowd to overlap much.
A few quick ideas though:
- Cross talk shouldn't bee too much a concern at the speeds the Arduino switches at. Outputs are also usually driven against less than 10K of output impedance.
- The 3 VCC pins are only present on original stickduinos, recent stickduinos have "VCC, RESET, and GND" in the top left instead.
- With all the board space available, you could add a prototype area or a small boost converter.
- The Stickduino has 17 pins/side. Unfortunately, 17 pin female headers are basically non-existent. You might consider using two 16-pin headers and just ignoring the extra ground on the lower right and the extra VCC on the upper left.
Feel free to hit me up for some collaboration.