Almost forgot about this one: It won a few design awards years ago. There was a little bit of publicity, and they were going to sell them -- but I haven't heard anything since.
It's called the "Micro Compact Home". It's a house in a 9 foot cube. They can be towed, air lifted, or set in place by a crane (or a bunch of college students, provided you supply enough beer).
The layout is weird, but effective. You walk in the front door, straight into a "wetzone" bathroom. The floor allows water to drain, and there's a toilet and a shower head. From a functional perspective, you could leave dirty / wet shoes and clothes here, and keep the house part clean. From there, you walk into the rest of the "house". A galley kitchen is on the left, and a sunken dinette on the right. The dinette seats are at floor level, with foot space below deck. Above the dinette is a full sized, extra long bed that folds up and out of the way. The dinette table drops down and forms another bed, at floor level. To the right and back (in line with the bathroom) is storage.
I really like the modern styling, but I'm partial on walking into the bathroom. Either put a curtain in front of the toilet (so you don't see it when you walk in), or have a second door where the small window is, at the opposite end.