Lego has a very cool cad program where you can build and design your very own creation, and when you are done, you can buy the kit! This kit would cost $213.31, that's not going to happen in this recession. but I can enjoy an unlimited amount of Lego with out all the mess.
While nursing a day long hangover, I built a model of a Frank Lloyd Wright Usonian inspired house.
I got the architectural reference plans from this site
The home is an approx 350 square foot house, with all the amenities of a plastic house. No heat or a/c and nor a washer hook up. But only plastic people can live here, so I don't think they will mind.
Here are some shots from Lego's simulated realistic environments:
Here are the screen shot details so you can see what the inside looks like.
Opps I left the pizza on the counter.
Here you can see the tiny breakfast nook
I think I found a fun new medium.