In "Who Killed Aiyana Stanley-Jones?", a grim portrait of a once-great American city, Charlie Leduff writing for the Nov/Dec 2010 issue of Mother Jones describes how Detroit fire stations have solved an important problem:

[the fire house is] alerted to fires by fax from the central office. (They'd jerry-rigged a contraption where the fax pushes a door hinge, which falls on a screw wired to an actual alarm.)

Overlooking the sad need for such a primitive system, it's a Smart Home Hack to be proud of.