I don't know what I need one of these for, but I need one. I just do.

Question is, what should it do? I mean, kicking off a build just doesn't seem significant enough. Bringing down the live systems perhaps?

Whatever it triggers needs to be acompanied by a klaxon, a red flashing light, and a voice counting calmly but loudly down from ten minutes, like the starship destruction sequence from Alien. Dry ice optional.