The new trend here is a wheel off. I completed a folding bike a la Christian Nau. Needs a larger and real sail (a shower curtain at the moment ), but the mast step works.
My friend bicikite - who usually sails on a two wheels kitebuggy - is going more radical with a completely different and risky design. You can follow his project on http://www.foilforum.it/covo-smanettoni/carrapaho-t4507.html.
I built a similar rig in school, IIRC it resulted in lots of detol and bandaids.
Later, I cobbled up a skateboard with a simple sail- its mast sat in a socket screwed onto the board. I definately remember that one costing chunks of skin, big bandaids, detol and lectures from the opressors that fed me. (my long suffering parents)
but - what the heck, chicks dig scars!
After that I started drifting towards stuff with rollcages and seatbelts.
Your efforts seem to work a lot better than mine ever did......
I once rode/sailed a sail bike. It took a little getting used to but a lot of fun. I did the windsurf sail on a skate board thing (aka death skate) too on dry lake beds. A buddy of mine hit a cow pie at speed on a dry lake bed skate sailing. Stopped the board instantly you can guess the rest. That was his last day on it. Broken rib. My personal rule was sail no faster than you can run. Here is another take on pedal power.
Last week-end great event with Class 8 and landyacht regattas and sailing bikes freeride. Very happy with the Breezycletta II, needs some refinements but works great