A little while back I had read this spin fv-1 forum thread about making a zero cross and synthesizing a basic waveform, there was some really good info on ways to eliminate the harmonics that cause lots of funky crazy warble and stuff. I'll look around for it. I had also made some stuff like this for singing controlled synth on the Nord g2 and I'll see what I did there to get the pitch to track better... I think it might have just been adding a slew of some sort after the zero cross.

The reason I mention is I was trying this with my voice and the zero cross detection is not able to track the harmonics of my voice which ends up in pretty much white noise:/. I really wanted to play with this but I don't have an electric guitar at the moment hehehe, so I'll see if I can figure out the way to smooth out its response for voice.