Found this on Chow.com listed as one of their picks. The best deal I found is on the website
http:// www.customcurling.com/proddetail.asp?prod=DropStop2pack [1] which was also posted on the chow.com review. They offer free shipping for $50+, 5% off for the holidays (no code necessary) and an additional $5 off if you use google checkout!

I think they're cute gifts and great for more formal, white tablecloth gatherings, too! They are little Mylar discs that you roll to fit in the wine bottle.

SOURCE [2]

SOURCE [3]

chow.com's review:

No More Red Wine Stains

Handy gadget keeps wine dribbles off the table.

Just in time for holiday dinners and lots of red wine drinking, I spied this great invention. It’s called Drop Stop, and it’s a simple circle of shiny silver plastic-y stuff that you roll up and stick in the mouth of an open wine bottle for pouring. It acts like the metal versions you see in restaurants, so that when you set the bottle back down, the wine doesn’t dribble out the side. No ruined tablecloths.

Drop Stop, $5.95 for two

http:// www.chow.com/pick/6801 [4]