OK, first real session went well. I put him in his skijoring harness (no, we haven't ever skijored... i'm still learning to XC ski) and bought one of these: wacky walk'r. I attached it to the lower section of the rear rack on my commuter with a carabiner and started out just walking with the bike between me and him. once he got over the initial discomfort with the whole idea, i started riding and voila! it worked! He only stopped once to <try to> pee but didn't try to chase any bunnies or squirrels.