We have a nice 4-wheel bike we use for lots of things. The link below:
http://strans.org/pedaled_sweeper.htm
explains how we attached a sweeper and swept the bike lanes by bike power. Last week we welded a hitch to it and towed several types of trailers (boat, heavy machinery, etc.) to move 400 bikes to a festival. Missoula is surrounded by mountains, but the valley is _flat_.
Lots of trailer designs are flying out of the shop- a no-weld version with forks, stems, tubes, and a piece of tire for a hitch. a kayak carrier made from aluminum crutches (a wheel fits exactly where the handles on the crutches are). shopping carts with the bottom wheel assembly taken off and 2 rear triangles (a use for those walmart rear triangles) bolted on.
eventually we'll get pictures onto the web. we have instructions for the 'crutches trailer' typed up- email me if you want them.
my favorite load carrier is the 'long john.' so smooth and versatile. see 1st 2 pics at: http://strans.org/bikestyle.html
-Bob G., Free Cycles Missoula