Defusable Alarm Clock is now on sale.
Clock Features:
Functions as an ordinary alarm clock with snooze alarm and two alarm modes (normal beeping, and countdown sequence).
There's no battery backup, but the current time is always preserved in non-volatile EEPROM memory, so you don't have to reset the time after a brief power interruption or if you move the clock from one place to another. Alarm time and mode are also preserved in EEPROM.
When you press the big red button, the detonation countdown sequence starts. You've got 10 seconds to cut the correct wire or the clock "explodes" with flashing red LEDs. (You can set the countdown sequence to higher values -- see detailed usage below.)
The wires are held with screw terminals so they are easily replaced. If you don't want to actually cut the wires, you can leave the screws a bit loose and pull the wires out instead.
Requires a common 9V DC power adapter with a 2.1mm center-positive plug. The adapter should be rated for at least 200mA. This is also available in the nootropic design store.
The clock can also be powered by batteries. Six AA, C or D cell batteries can be used to provide 9V. C or D cells will provide the longest life. The clock draws about 90mA of current.
The Defusable Clock is completely hackable. It is powered by an ATmega328 microcontroller with the Arduino bootloader, so you can easily reprogram it to your liking. The software is all open source!