I don't need this test to tell me I'm a genius. (Though I did get 21.) My class could get 15-20 each by themselves, 9th graders, and trust me, we're not all geniuses.
Mensa tries to cover itself at the bottom of the page by saying that this type of test only measures certain types of geniuses, blah, blah, blah.
This seems to me like one of those things that circulate around the office, usually coupled with "send this 2 10 co-workers or the angel of death will visit u in ur sleep 2nite!1!11!" Especially coming from Mensa, I would expect better....or maybe I wouldn't.
edit: Wonderful! On further review of the FAQ page, we come to find that this test is not actually a "MENSA" test, but a test that had been circulating around for years and was sent to the author by somebody who may or may not have been affiliated with Mensa at some point. Wow, you're cool. Proud of yourself? You should be.