ARM7 mini quad with xbee remote
Also take a look at the DIY-drones post I made, (it made it to the front page!).
Using an Phillips NXP LPC20148 ARM7 processor, a Nintendo Wii motion+, and some xbees I've made a really stable platform for quads. (mode details here) It is running FreeRTOS which makes it very expandable in the future. My old frame flew great with it, but I wanted something smaller. Enter my new carbon fiber mini-quad:
My props from hobbyking were very unbalanced, but easily fixed with some electrical tape:
This one is from last week.