What's Your Coolest 555 Timer Project?

[d1983]

I have just designed a brake/blinker system using high intensity LEDs and a 555 timer and it gave me an idea for a post:
What's the coolest thing you've done using a 555 timer?

 

[3trQN]

On work experience as boy i made a Variable speed blinking LED display with an offensive message. And i placed it above the bosses office door for giggles.

 

[triden]

I made an automatic car starter with a monostable 555. At the touch of a button it would crank the engine over for 3 seconds unless it started sooner, in which case it would stop cranking. Pretty click and neat !

 

[Averagesupernova]

I made a narrow band frequency detector by using 2 555s as missing pulse detectors.

 

[Cheech]

555

Like The car starter, I made an adjustable jacobs later using an ignition coil

 

[Danger]

I know nothing of electronics, but I did once use a chip that looked very much like a 555 to prop up the short leg of my draughting table. Does that count?