Yes, that's right, I'm currently obsessed with Lego. Yes, the little plastic bricks that children play with-- except there's a whole group of AFOL (adult fans of Lego) I recently found. They build amazing projects... check out the work of Nathan Sawaya. Or look at some of these Lego buildings in a flickr group.
Nothing I make is that complicated, of course, as I mostly take the few sets I have and use those pieces to build something else. Take the log cabin... I re-built it into something I call a log cottage:
and, from the back... a bed upstairs and a sink and eat-in-counter. You have to use the fireplace out front if you want to cook. ;)
It was a fun challenge because I could use only the pieces from that set (which is why there's a green stripe on the loft floor), and I like what I created!