I soldered a row of red LEDs to a small piece of perfboard and hooked them up to an msp430 microcontroller that had been flashed using mspdebug with code I compiled with mspgcc4. TI doesn't yet have a stable release of their CodeComposer software out for Linux yet, but the tools the open source community has put together to program the msp430 line of chips work very well.
This post on Hack-a-Day was really useful in getting started with programming this line of chips in Linux, as are the forums on 43oh. The TI Launchpad has been a really good, low cost way of getting myself into microcontrollers and electronics. I've learned a lot so far. I have the book MSP430 Microcontroller Basics, but since I keep meaning to finish Colin Moock's Essential Actionscript 3.0, it'll have to wait. Til then all the bite-sized tutorials on the net will do.
My source code is not pretty or elegant, since I know only enough C to do basic things, but the LED Chaser works fine:
1/6/11 - The two AA batteries powering the LED chaser finally gave out. I'm surprised they were able to run the msp430g2211 and 8 red LEDs for just over a month! I'm sure with better use of the power-saving features available to the msp430 line I could squeeze out a bit more life out of my proto-Cylon. It's something I'll have to play with as time permits.
1/7/11 - Here's a more advanced version done by someone brighter than myself: link