I think a trip to your local radioshack or electroics componenets reseller wodul be a good thing for you. I can think of about 50 ways to do this, but won't want to spend my time (probably 2 hours) to write it out for you. I will say that with some super glue, and a single switch from radio shack (or however many taps you have, so all look the same), some doorbell wire and a soldering gun/solder you can do this in an afternoon.
hooked it up to LED lights using a 9v battery for power too, so it plays Handel's "hallelujah" and lights up the tap, also possible to get an LED into the tap so it lights up the beer
Hooked up to a doorbell
Hooked up to a car horn
Hooked up to a trap door
Imagination is key.
Primary: Eds Aplfelwine 1/19/12, Twin peaks DIPA 1/10/12, BJK 2 hour IPA 12/9/11
Secondary: Hoppys 420 IPA (infected) 10/20/11, Colorado Wildflower Cyser (infected) 10/21/11
Bottled or Kegged: Over Inflated Rubber Thingy 1/20/11, Fiddle Barn Stout medium american oaked bourbon, 7/20/11, Pumpkin porter 12/17/11, KIPA: Oaked IIPA, ~1/2/2011 (started ~10/2/11), 1/27/12 6% abv sort of Hoegarden clone,