At last weekend's awesome MAKEr Faire — where everything was steampunk, apparently! — steampunk / goth band Abney Park debuted this fantastic violin mod on stage for the first time. Modified with vacuum tubes and blinking LEDs, the violin was designed by Molly "Porkshanks" Friedrich, and the vacuum tubes pulse with color as the strings vibrate. But I'm going to re-echo Slashgear's question on the sound quality: don't violins require a certain form for optimal tonality?
Abney Park Violin [MAKE]