A quick look at the rapidly expanding Arduino project base will show the versatility of the Gertboard. Additionally, a ROHM BD6222HFPmotor controller adds 18V @ 2A port for motor projects. There is also a 2-channel 8-, 10-, or 12-bit digital-to-analog converter alongside a 2-channel 10-bit analog-to-digital converter. To top it off, 6x open collector divers capable of 50V @ 0.5A, 3x push buttons, and 12x buffered I/O makes this expansion board a solid choice for those who want to take the Raspberry Pi beyond casual.
The Gertboard can be picked up for $49.99 at Newark/element14.com.