Yes there is -- I do it annually at the trivia contest we stage at
PowerPoint Live. As long as you do not need the timer to traverse across
multiple slides, it can be done with animation. If you want it across
slides, you need a VBA solution. I'll give you the basics and you can come
back at me if you need more details.
1. Custom Animation has controls for determining the duration of an
animation.
2. One of the animations you can apply is Spin, which functions like rotate.
Setting up a clock face and a second hand and/or minute hand is not
difficult (just ovals and thin rectangles), and applying a spin to the hands
is also straightforward. The tricky part is that object's only spin from
their center, not from an end, so the first time you do this, you'll
probably see the minute hand just twirl around, instead of appear to be
moving around the face of the clock. To address this, the object that spins
needs to actually be two objects, grouped together to make one long one,
each of equal length, one visible and one completely invisible. That way,
when the compound object spins around its center, it will appear as if the
visible part is rotating around.
I can send you an example, if necessary. Although I suspect you might have
fun trying to figure it out on your own...