Niibe is currently developing a minimum USB computer with STM32F103CB, named Flying Stone 01 (FST-01). This is designed for Gnuk and NeuG standalone.
The photo is experimental implementation.
It would be great to manufacture many FST-01.
During this development, Niibe found an interesting site in China.
Please vote for FST-01 at that site: http://www.seeedstudio.com/wish/?p=783