In case you hadn't heard, there's a controversy about his birth certificate. For some reason the State of Hawaii won't release it. The version on the net is said to be fishy by many people. You can read about it here, where they judge it a valid birth certificate, and here, where they maintain that it's a forgery. Or you can just google "Obama" "Birth certificate" and find lots of stuff pro and con.
Anyhow, if you want to get your friends interested in the issue, I'm making this available as a greeting card here.