http://www.youtube.com/watch?v=iAouuLoPO4I 
that is no viewer-hunt guys... I heard those kind of synthetizer sounds quite often in various electro tracks. Its just for fun - no question about that (although I could imagine a place for this sound in band), but its really unbelievable how authentic it gets out of acoustic bass
have fun with it - its just pressing the strings down so the string rings between both ends of the fretboard.