If you often lose power where you live, whether because of seasonal storms such as hurricanes or due to other problems with the electrical grid, having a whole-house generator can be very convenient.

Obviously a FG-100 (ebay is a good source) ATMega328p 28pin DIP microcontroller AVR programmer/ISP (the Makefile defaults to using a USBTiny ISP) AVR toolchain (eg avr-gcc, avrdude and gnumake) ...