Moon, Mars and Venus for about $20 an acre.

Found this on the News of the Weird Newsletter:

http://www.newsoftheweird.com/archive/index.html

For 23 years, Dennis Hope, 55, of Gardnerville, Nev., has operated a
business selling people "official" title to land on the moon, Mars and
Venus for about $20 an acre. Although others are in the same business,
Hope told the Las Vegas Review-Journal in September that he has earned
$6.5 million during that period (an average of $270,000 a year). He
says his idea was based on something he actually learned in school:
that the international Outer Space Treaty of 1967 prohibited nations
from owning celestial bodies but was silent about individual
ownership. Hope says he wrote to the United Nations, explained his
plan, and asked if they had a problem with it (and no one wrote back).
[Las Vegas Review-Journal, 9-29-03]