The pandaboard is amazing. I mean, dual core A9 processor, 1080p video with a DSP, wlan, 3 usb ports, JTAG, expansion headers in a neat tiny package all for $175? Damn.<p>It could be a seedbox, NAS and dedicated video / music player all in one, or you could use it for your next robotics project to do on board processing on your quadcopter!
Note that at least the $4.30 MSP430 does seem to have open-source support, e.g. <a href="http://mspgcc.sourceforge.net/" rel="nofollow">http://mspgcc.sourceforge.net/</a>,
FYI, If you want a full system, the Insignia Infocast, which is a Best Buy rebranded chumby, is in the $80-100 range. 8" touchscreen, 800Mhz ARM processor, and runs OE:<p><a href="http://www.bunniestudios.com/blog/?p=1435" rel="nofollow">http://www.bunniestudios.com/blog/?p=1435</a><p>it's a nice starting point, if you're looking for an already mostly there system.
I'm not sure why they always seem to be left out these days, but Microchip PIC micros are great for learning this kind of stuff. There are lots of cheap programmers available, most of the chips are available in DIP format to use with a breadboard, and they have the most generous sample program ever.