The AVR is a 8 bit RISC microcontroller family produced by the Atmel Corporation. The AVR processors are good processors for hobbyists, there are free development environments available and the processors can be burned in-circuit with just a few wires to the parallel port of a PC. The program memory is flash-based, so the chips can be erased and programmed again many times.
Here is a list of things I did with the AVR processors. This list contains projects which are stand-alone, and projects which better fit into another category of my website.