A quick google of "kayak cart" shows that the cheapest one cost $60, and most of them are over $100 - so forget that. I decided to make my own, and I did, and that's it in the photo. The construction should be almost self-explanatory: a pair of training wheels from Thrifttown ($1) are bolted onto PVC t-connectors, and the rest is made from tees and thick-walled PVC pipe, and a "pool noodle." If it seems like it needs a stronger frame I'll add another crosswise pipe to it. Improvements: I suppose the tees can be joined to the pipe sections with clevis pins to make a cart that can be disassembled. If the wheels were closer together then the thing could be turned upside-down and used to load the kayak onto the car. Bigger wheels would make the cart more usable on lawns, beaches, and gravel roads, but as it is it's only useful on hard, flat surfaces. Materials: training wheels from the thrift store or flea market four 3/4" PVC tees one pair each of 3/4" x #14 machine screws, nuts, and washers glue (I used Plumber's Goop), clevis pins, or sheet metal screws to join the PVC parts pipe insulation, pool noodle, or other foamy cushioning thinger The cost so far for the parts that didn't just come out of a junk box (that means the training wheels and the pool noodle) is about $2.25. Edit, October '11: This thing is usable, but it really needs to be sturdier, and the padded parts should be farther apart. PVC cement would be best for permanently joining the PVC pipe and couplings, but I don't like to buy that stuff--most of it ends up sitting in the can until it goes bad. December 2012: If you make one of these, plan to make a better one and keep your eye out for a bigger pair of wheels and some aluminum tubing from an old pair of crutches or something. A jogging stroller with an aluminum frame is a good source of parts.