Looking for Atmel AVR microcontrollers? We've got them! They're really, really good. Truly. And pretty inexpensive, too! Solarbotics has bags of them. Well protected, anti-static bags of them!
This ATtiny45V is an low voltage version of the ATtiny45 8-pin DIP IC with impressive capabilities!
|4kB||256B||256B||0 - 10MHz||1.8 - 5.5V|
The AVR series of microcontrollers are right up there with Microchip PIC products. Powerful, inexpensive, and programmable with some very good open source software (look up GCC), with a vibrant user community.
For a small, low-voltage, single-purpose applications, it's a cheap and powerful solution! Hmmm... looks like it'd be happy running on solar power too!