Originally Posted by Andy M.
I use a kitchen knife. Run the blade up the bottle starting at the bottom of the foil towards the spout. That cuts a quarter inch slice off the foil. From there it's easy to grab a corner and pull it off.
This is exactly what I do as well. I've seen a lot of people (including restaurant waiters) try to use the tiny little serrated blade that comes on a corkscrew and painstakingly "saw" the foil off around the lip. I realize that leaving the remaining foil on the bottle gives it an aesthetically pleasing appearance but, come on, it's for drinking!
We often have to quickly open hundreds of bottles for competitions, and the fastest way to get the foil off is the method you describe.