Originally Posted by TCav
The Tamron 70-300 Di LD that shoturtle mentioned would also not be a bad lens for shooting sports/action, and it would be stabilized on a Pentax or Sony.
It wouldn't be very good as it is slow to focus. You're going to make sacrifices in sub $200 telephoto lenses. Usually focus speed is one of those sacrifices.
Everything is relative though. It's probably as good as any sub $200 300mm lens. But whether it is "good enough" is another matter and will vary by individual.