Topic: Fernandes Sustainer
I think this is one of the coolest innovations to come along in electric guitar tech in a long time. I've never really been happy with any of the electronic / stompbox sustain gadets, as the sound never sounded natural. This Fernandes circuit actually emits a pulsing magnetic field from their neck pickup, which keeps the actual string vibrating until the player stops it. The bridge pickup then just operates as it usually does, so the the sustain is purely from the guitar itself:
Here's the whole rundown from Fernandes' site, and I see it can now be bought as a kit and installed in any guitar ... very interesting: