Dan Watson has designed this very tiny breakout board for the Atmel ATtiny10. He wrote a post on his blog detailing its assembly:
This breakout board is for the ATtiny10 microcontroller. The PCB is 0.25×0.325″ and uses 0.050″ header pins. The board could actually be made smaller, but I ran into the minimum PCB size limit on OSHPark. Despite the tiny size, I was able to include a 100nF bypass capacitor, power LED, and a user LED on pin PB1. That pin is also the clock pin for the programming interface, so it flashed when the board is being programmed.
Project info at The Sync Channel blog.