My oldest boy Jesse wanted a blocart but I couldn't justify the price.
As both boys had out grown their trampoline, along with some old windsurfer bits and wheel barrow wheels we built 3 of these for less than $200 each. They only take a couple of days to build. Cheap, quick and easy, great for 2 wheeling and 180deg. slideouts. There are 3 short movies on Google Video : Jesses landyacht. Enjoy.