A USB stick to interface with the tinyduino radio modules you have on kickstarter could be useful - remote control of a tinyduino from a computer. Idea 9 now?

Don't really know if it can be classed as tinyduino directly.

No: 8? A shield for interfacing with another platform, namely the Raspberry Pi. I'm guessing most of the people here own an rPi, and as such a shield to interface with one would be a useful toy *ahem* tool.

Not to be funny, but the arduino uno is not a CPU powerhouse. The raspberry pi is more powerful, and can handle openCV, for example.

No. 7: You've created a display shield, but what about a shield that drives analogue or digital displays, perhaps with a small GPU module to palm processing off on. Driving analogue or digital displays is difficult, and not something arduino is massively well suited to, but it would be useful - driving any display is a lot less restrictive than driving a specific display.

Probably-not-possible-ideas, great fun.

No. 6:
A display add-on for tinyduino, or perhaps arduino in general, that provides a a Liquid Crystal on Silicon (LCoS), field-sequential color, LED illuminated display using a collimating reflector (stolen from wikipedia, it's the tech used in Google Glass's display, very practical for wearables) would be great but probably impossible.

As far as I'm aware, tinyduino is the smallest arduino around, so is well suited to wearables. A wearable-specific screen would be very very good for the platform.

A board to fit tinyduino with stepper motors - tinyduino idea 5! Driving stepper motors usually requires either extra load on the CPU or an external drive board, so a board to drive 2 or more stepper motors directly would be very practical.

Again with the robotics!

Another idea, 5th now. Some of these have been suggested before I think, but putting them up for a plug anyway! A shield for controlling extra PWM devices or servos, with a battery connector and multiple PWM tie downs.

Still plugging the robotics here - biped walkers are hard with just 6 PWM points.

Idea no.... 4 now? A shield where you can mount two tinyduino shields next to each other, for example a radio and bluetooth module next to each other. I can't imagine it being too difficult to produce...

Should solve some signal problems

Idea no. 3, again shamelessly stolen from regular Arduino, is a shield that can be used alongside an IR remote for remote media control (as one idea). Could be useful somehow I'm sure.

Idea came from: http://www.dx.com/p/ir-receiver-module-wireless-remote-control-kit-for-arduino-1-x-cr2025-135520#.VDmlivldUnU

Idea no. 2.5 (related to the Sonar Shield) is a shield for mounting another shield at 90° to the one previous to it, for mounting a sonar shield or other sensor in a more appropriate position for use.

More robotics toys, perhaps?

Idea No. 2 from me, a shield with a sonar rangefinder on board, similar to those available for normal arduino shields but sized appropriately for tinyduino.

Robot sensors, anybody?

My idea for tinyduino suggestion 1 is that you create a cable with a male shield connector on one end and a female one on the other. In this way, you could mount a shield remotely from the stack, such as for wearable applications, enclosures, and similar situations. For example, my use for this (personally) is that I could then mount a tinyscreen inside my motorcycle helmet to display information in a space where the whole stack would not fit.