I have been doing some work with the STM Discovery Board. It features an STM 32F407 ARM processor than can clock at 168 MIPS peak. A real screamer. And at less than $15 per STM is practically giving them away.
But the pin out of the board is a little odd for doing parallel port projects. So I decided to rectify that by designing a little interface board that puts the pins in a more regular order. The STM Discovery plugs into the interface so if you want to use the Discovery later with a different interface all you have to do is to unplug it. The connector is a Samtec SSW-125-01-T-D. Digikey has it in their catalog but they don't currently stock it (bug them). You can get it directly from Samtec.
Here is the schematic and here is the parts list. Both in pdf format.
OSH Park is selling the boards for $4.90 each.
Engineering is the art of making what you want from what you can get at a profit.