If you're looking for a timer like one you'd use in the classroom:
So this is nothing fancy, but a YouTube timer would work great. Use the YouTube external tool (as opposed to pasting the URL and getting a preview on your content page) and you can play the timer without altering the look of your page.
That link no longer works. - The original thread has been put into deepfreeze and is no longer accessible without permissions.
Is there another way to access that information?