I've used my mountain bike to troll for turkeys in the spring. Just sling the shotgun over your back, take the bike out of the car, throw in your mouth call and go.

There's a local bike trail that covers 20 miles of isolated woodlands along a river that winds down through the mountains. You cross a few roads, but you can really cover some ground. I just stop every 1/4 mile or so, and try to locate. Sucks when you get one though - there's just no easy way to lug him out. I like that game cart idea, by the way. Pretty slick.