If you have a bottled beer that requires an opener and you have no opener, here's a trick you can use to get your beer open. Take a dollar bill (or other denomination, or some other sheet of paper) and roll it up into a very tight tube. If you are using a dollar, roll it so that the tube is short, not long. Once you have the tube, bend it in half so it makes a less than or greater than sign (< or >). You can then put this wedged under the bottle cap, squeeze it tight under the bottle cap, hold onto the bottle, and then pull the cap off. It's a little tricky to get the hang of. But once you get it it's really easy to open beers this way.