A LinuxDevices article mentioned a new PC/104 form factor ARM9 microcontroller made by EMAC that might be useful for robot hobbyists. The board, called the iPac-9302 is based on the Cirrus EP9302 SOC, which uses a 200MHz ARM920T CPU with a MaverickCrunch floating point math engine. The board supports up to 64MB of SDRAM, 32MB of flash, 256KB EEPROM, and a PLD which can be reprogrammed to support quadrature decoding, stepper control, or other custom tasks. It supports a lot of I/O including AC97 audio, 10/100 ethernet, 1 RS-232, 1 RS-232/422/485, 2 USB 2.0 port, 16 processor I/O lines, 16 PLD digital inputs (5v), 8 digital outputs (25ma), 8 high-drive digital outputs (500ma), 9 synchronous serial I/O lines (SPI/I2S), 3 PWM I/O lines, 5 channels of 12 bit A/D, and 2 channels of 8 bit D/A. You can also get an optional JTAG adapter and screw terminal board for all that I/O. And, yes, it runs Linux. The best part is that the pricing starts at $150 in single unit quantities. For more details see the iPac 9302 manual (PDF format).