Sparkfun & Arduino announced today the new Arduino Pro ($20) and Arduino Pro Mini ($19), two 3.3V “low-cost, low-profile boards intended for advanced users and for convenient embedding in long-term projects”.
The Arduino Pro is shield compatible (but 3.3v, beware) and includes a connector for lithium ion batteries. The Arduino Pro Mini is well….mini at .73″x1.3″ (while the Arduino Nano is 0.73??? x 1.70???, with a mini USB port and 5V operating voltage but costs $50).
Both are great candidates for permanent projects, I’ll evaluate them when I get back from my September liveaboard trip.