+ one on the Dahon or similar.
I did not read the whole thread.
You should get a folding bike with 20 inch wheels since it is more compact and everything, not just the frame, will fold. Dahon fits the bill. They are quite nice bikes and sacrafice very little in terms of riding experience.
In general, never get the cheap walmark type bikes, go for the bike shop quality bikes. walmark bike is fine for riding to the bathroom and back, but they are such poor quality bikes in general. you get what you pay for in the bike world.
Look for used bikes if price comes into play.