The RBBB from Modern Device Company is a wonderful little Arduino clone. If you have a Arduino project requiring a small footprint or an inexpensive dedicated board, this is a great solution.
I discovered the RBBB while looking for a cheaper alternative to the official Arduino board I used in developing my Northern Lights Indicator. On sale, buying 5 kits, these came out to about $9 each. That is a huge savings over the $35 Arduino Diecimila.