I encourage everybody to take the online IQ test here.
You just might qualify for their membership. I didn't, I was tested to have an IQ of 85, which puts me in the "low intelligence" category.
Alternatively you can try Mensa. About 150 people took the exam last July 1 at Oakwood Premiere, and unofficial results are already online. I heard that Bruce Willis, Constantine, Tom Cruise, and Meg Ryan passed their exam.
What I now know about my IQ will properly place me in my right place. I hope it cures me of my delusions regarding my brilliance.