There are lots of small version of Arduino around such as:
Pro Mini: https://www.sparkfun.com/products/11113
Pro Micro: https://www.sparkfun.com/products/11098?
Arduino Nano: http://www.arduino.cc/en/Main/ArduinoBoardNano
Pro Mini: https://www.sparkfun.com/products/11113
Pro Micro: https://www.sparkfun.com/products/11098?
Arduino Nano: http://www.arduino.cc/en/Main/ArduinoBoardNano
And the Arduino Nano seems to no longer be carried by Arduino themselves, I was unable to find it in the shop.
I think this looks nice since it's based on a more recent AVR chip, that has on-board USB so that even the small form factor doesn't mean the board can't have a "native" USB connector.
Most people are probably only aware of the arduino uno which uses the 328p chip, but there are probably 20 other atmel chip models that are also "arduino compatible". I typically use the attiny85 because my one-off projects rarely need all the pins on the 328p.
Most of the arduino-like boards have a 10 bit resolution.
There's also Tinyduino on the making: http://www.kickstarter.com/projects/kenburns/tinyduino-the-t...