Are your running 10.4.8? Do you have a mouse with a scroll wheel? Try this… hold down the Control key and move your scroll wheel up and down. Cool, huh.
This trick also works on newer laptops that let you scroll by using 2 fingers on the trackpad.
You may be able to do this prior to 10.4.8, but I’m not sure how far back it goes back.
found via macdevcenter