Yes, just plain old aluminum foil! Here's what I did. I cut 3 regular sized pieces of aluminum foil.
Then I smooshed them up into balls (not tight balls, rather loose).
Then I just tossed them into the dryer with my wet clothes.
How incredibly simple is that? Then when my clothes came out, there was NO static cling. Now keep in mind that I have not yet tried this in a load with a lot of synthetic fibers. Anyway, these three balls have worked for 5 loads thus far. I do not know how long they will last....indefinitely, possibly? My thoughts are if they need replaced you can just recycle these....very little environmental impact!
Give it a try and let me know how it works for you!
UPDATE 20 Jan 2012
This method works for 3-5 loads. It works best when there are fewer items made with synthetic fibers. Just use this method for 3-5 loads then recycle the aluminum and make more balls! :D