As reported in various media (CNet, Wired, etc) there is a new sport called "googlewhacking" where you try to use Google to find exactly one web page that has a pair of words. If more than one page matches, or no pages matches, the pair of words does not count.
For some examples, see http://www.googlewhack.com/tally.pl
Hmm, now that I think about it, you can also cheat if you're patient enough. If you find a pair of words that get zero hits. Create a web page (maybe an anonymous slashdot post) that contains the pair of words, wait for google to find it, then you "win". But I'm sure that any judges would get suspicious if they could trace the page back to you, or if the page did not use words in a "reasonable" way.