Challenging your own knowledge with timed quizzes is proving more and more popular. As of Saturday, Dec. 6, my How Many Xs Can You Name In Y Minutes? post now features over 1,000 different timed quizzes!

It all started at 12:31 PM EST, back on February 27, 2007, with the Ironic Sans post 50 States in 10 Minutes.

The meme has spread so far and fast that I now have to keep up with at least 10 different sites that specialize in timed quizzes, in order to make sure my list stays current!

It's not difficult to see who dominates the list, either. Out of the 1,013 quizzes on my list at this writing, Sporcle accounts for 698 of them! Sporcle originally started with the idea of being a site focused on advice for picking winning sports teams, and they featured a few How Many Xs Can You Name In Y Minutes?-type quizzes as a diversion. However, the popularity of the quizzes proved so great, their focus turned to them as their specialty. Sporcle also just hit a special timed-quiz landmark of its own earlier this week when they reached more than 10 million plays of their quizzes!

Sporcle was also recently generous enough to thank Grey Matters for helping their site! As a reponse, I'd simply like to say you're welcome, and express my hope that they keep up the great work!

If you have a blog or a website, you can be part of the fun (and the list, too!) by creating your own timed quiz with the Grey Matters Timed Quiz Generator. Instructions are linked on the page, and the generator creates HTML/Javascript/CSS code that you can put on your site. Even if your blog doesn't accept full standard HTML, Javascript & CSS, you can host it separately, and simply include it in your blog via an iframe tag.

Mogroware was the first site I'm aware of that featured a timed quiz generator.

Please let me know if I've missed any of your favorites timed quizzes, so I can add them to the list!