php / mysql quiz

Im looking for a fun quiz for a dating website that i hope would help bring visitors to the site. my site is php/mysql and i have a membership system so can restrict the quiz for registered users only if i wish. Flash is an option, but im ok if its html/php based. Id like to be able to manage questions via a backend admin. be nice to change the quiz on a set basis, say once a month and be able to store the scores of all who did the quiz and show the winner for that month's quiz on home page for example. A way to log the website username would be nice so they can't do that quiz again. id also like the facility for a person completing quiz to send an email and challenge one or more people they know as a way to draw them to the website. Any other ideas are welcome