Ya NanoNote feature requests
Some method of adding external peripherals or devices and external connectors for existing features.
Some thoughts that come to mind:
Several GPIOs - for implementing I2C, 1W, etc via bit-banging
CF - not just for flash, but also for CF WiFi, CF GPS, etc
WiFi - could be low power if a pair of decent antennas can be built in to the lid
ZigBEE - 1mW should be enough for anybody :)
UART connector (both ttyS0 and ttyS1 on the same connector)
An "expansion port" could be created that would combine more than one of these into a proprietary (but documented) interface using standard connectors, a single- or dual-row 0.1" pitch header (could be male or female), for example.
With the expansion port, it would be easy to create a prototyping board that would either plug directly into the port (remember the Handspring Springboard modules?) or would connect via a short ribbon cable. This would encourage development and help with troubleshooting.
With a little work, the external modules could supply power independently to the devices on the module or even power the Ya, appearing as a 2nd battery, reducing the need for a larger battery.
When using the expansion port or CF, etc, the device would not necessarily need to be contained within the Ya. For instance, the CF card connector could be about 1/4" inside the case, just enough to hold the card securely.
if doing a expansion port, perhaps one could borrow the layout bug labs use on their modules? http://bugcommunity.com/wiki/index.php/Exploded_Connector_Diagram