Remember the guy who said he owned the planetoid Eros?

http://www.erosproject.com/

Probably never even heard of it before the NEAR mission, I am sure.

And there were three guys from Yemen who said they owned Mars. Might have more claim trouble with them.

http://www-cgi.cnn.com/TECH/9707/24/yemen.mars/

Then there is the guy who sells lunar real estate from his Lunar Embassy:

http://archives.cnn.com/2000/TECH/space/11/20/lunar.land/

Of course the day we really do start having a permanent presence in space, all claims to other worlds will become serious legal battles, as the corporations and governments realize just how valuable these places are.

Why, one average planetoid alone contains rougly $5 trillion in nickel. And the water ice in the comets will be priceless to colonists and interplanetary vessels. Watch the Kuiper Belt become an early target for colonization.