If you already know how to work with animations in Powerpoint, this is the template that I used to create my Powerpoint countdown timers (see my other products). You can use this template to create your own timers of various lengths. The timer displays both the number of minutes and the number of seconds remaining. When it reaches 0:00, a red "Time's Up" signal flashes. The timer is pretty easy to create (and manipulate), actually. It's just labor intensive, so I figured I'd do the labor for ya.