Does anyone know of a decent guitar synth I could pick up on ebay or somewhere to just mess around with? Not looking for anything too fancy, just want to be able to lay down some tracks with different instrument patches using my guitar. Basic functionality is fine...

Everything I've heard or read says Roland is the only one that actually works well. They have a few models I haven't tried one, though. The current GR-20 MIDi synth comes with a pickup that can be temporarily mounted on any steel-string guitar and sells for less than $400 on Ebay. Andy Summers used earlier models with the Police but they were much more expensive. The Roland V Guitar synth is a lot more flexible but also costs $1500 new. The main difficulties, I hear, are getting one that tracks all notes well and handles polyphony well.