My latest obsession is flying radio control planes. It's something I've wanted to do since I was a kid of ten or twelve. Only in recent years have I come back to it. 
Now every Sunday is spent at the flying field, learning how to fly (and to build) radio control planes. Now, these aren't your Dad's planes. Some of these puppies are pretty damn big.
My trainer (the plane on which I learn) has a six-foot wingspan and a motor that puts out about 1 horsepower. The prop will also cut your fingers off if you are foolish enough to stick them in it.
I've seen planes at the field large enough that they require a small trailer to carry them (so a wingspan in excess of ten feet).

I've just about finished building my first plane (the trainer was something I purchased pre-assembled). It's called a Gremlin and it's for air combat and weighs about 3lbs. It has one of those motors that almost make 1 hp and should approach speeds of 80-100mph in the air.
I love the attention to detail necessary to keep these babies flying and the motors are just little jewels. I've recently gone on an EBay buying binge and now have something like five motors--and only two planes at the moment.
Next plane after I get the combat plane airworthy (flying this Sunday) will be a SPAD. Not the WWI fighter but rather a Simple, Plastic, Airplane Design. It uses corrugated plastic (Coroplast) for wing material and the fuselage is made out of aluminum angle iron stock. Not pretty, but very, very cheap to build. I think my total cost on building one with a six-foot wingspan will be something like $30. (Free plans are available on the site.)
Posted by artandscience at September 3, 2004 10:00 AMYou've seen the RC B52 video, of course?
Posted by: paul at September 3, 2004 11:55 AMNo.. by all means, give me a pointer. I've heard it talked about and have seen references to it in print.
Now I'm going to look for it (courtesy of my Starbucks high-speed connection).
Posted by: stefan at September 7, 2004 09:34 AMTo do you one better, have you seen the B-52 crash video?
It's at: http://www.scaleflight.com/b52crash2.wmv
Very sad.