You can cut a beer bottle using string dipped in acetone and then setting it on fire. The video is a demonstration. I like how the guy in the video shows you some great uses for the bottle after you've removed the top. Apparently it makes a great toothbrush holder or place to store desk supplies. While I did enjoy this novel approach to glass cutting, I already have my own bottle cutter. It's called the sidewalk. You may not be left with a toothbrush holder afterwards, but it will significantly decrease foot-traffic in your neighborhood.
Cutting a Glass Bottle with String [techeblog]