So you've done a lot of work with Arduino, but your latest project just needs more OOMPH? Enter SimpleCortex. It's development board that's pin-compatible with Arduino shields yet offers a lot more bang for your buck. Read more after the break....
SimpleCortex is based around the ARM Cortex M3 microcontroller with 512KB flash, 64KB RAM and it runs at 120Mhz. IT also offers a built-in debugger, a whopping 40 I/O pins and built-in Ethernet and MicroSD ports as well. It runs off the CoIDE (Windows only - see their getting started page for details) and is fully liscensed under CC-BY-SA with Eagle files for the boards available here. They're sold out of the first batch already (The Hack-A-Day effect) but they're expecting more shortly. The board is available for order from iteadstudio (click here) for $45, which is not a bad price at all considering what you're getting.
Check out a few more shots of this beast and an I/O listing:
Click the I/O list below for a full-sized image