Fire Alarm Clock

For the really, really, really sound sleeper (or in case you want to wake up the entire neighborhood), Alan Parekh of Hacked Gadgets Forum cobbled together this masterpiece: an alarm rigged up to a fire alarm bell!

This hack takes a standard cheap alarm clock, some interface components and a fire alarm bell to get the job done right. Normally these small alarm clocks use a piezo buzzer to attempt to wake you up. The alarm signal is hijacked from the clock circuit board and used as an input to the interface board.

Link - Thanks Alan!