You will definitely need some materials and they're relatively inexpensive:
1 (or two if you want to make matching floggers) dowel rod measuring about 7-8"
1 roll of duct tape
1 pair of good scissors
1 ruler that measures about 22"
1 piece of sand paper
In regard to the dowel rods, if you purchase them from a hardware store and choose not to get them cut in store, you're going to want to have a saw handy to do it yourself. Most hardware stores will cut the rods for you (I know Home Depot did for me). With the duct tape, I'd suggest purchasing solid color tape as opposed to that with anything printed on it. The print tape costs more and doesn't have as much to it as a solid color. If you want a multi color flogger, purchase more than one roll.
I hope you can join us for our discussion on May 18, 2011! Mark your calendars for this discussion so you don't miss out!