I got to thinking about this during the recent hot weather. The paper towels I use are the 'select-a-size' type, which allow me to use just the amount needed. I have been washing my hands and face a lot and would walk into the office to log on to email still holding a small, damp paper towel. Those have ended up next to the computer; there are three here right now! Cats sitting next to the computer sometimes play with the crumpled paper towels. I've started rounding up the handful of used paper towels that accumulate each day and putting them into a plastic container in the kitchen. Then, when there is 'something'--usually icky-- on the floor, I just grab a few of the (dry, clean, crumpled) paper towels to use to wipe the floor. I am noticing a difference in my paper towel usage already.
If you need a reminder, or would like to remind others to reuse their paper towels, here is a great sticker to place on the paper towel holder or rack. Maybe order a few at about 20 cents each. It's a small cost to save 100 pounds of paper, which the stickers have been shown to do!