ZeroDev

While surfing the web today i found an old funny hack (discovered in the 2006) that let your HP scanjet scanner to sing!.

In some HP ScanJet products (i.e. 4c) Scanner Control Language command set (aka SCL) includes an unofficial PLAY TUNE command documented here by HP.

This hidden PLAY TUNE "feature" can be used to to produce audible frequencies (actually emitted by the scanner electric motor ) the result is amazing.. there are many videos on youtube showing singing scanners in action performing songs like:
Per Elisa
Ode To Joy
Vivaldi Spring

Who discovered this feature wrote an application and 2 samples (easy to customize, all the stuff is well documented and open source) check it here and have fun (if you are a lucky HP scanjet owner!)