There are some programs you may use.
Primarily intended for emulation purposes I belive.
Mo'Slo; there is an older Version that's trialware, can be found here:
Mo'Slo
EDIT:
He he, beat PvK.
Here's a page full of slow downers:
Slow it down
[ February 29, 2004, 19:20: Message edited by: Ruatha ]