Before venturing Down Under, away from the safe surroundings of Denmark, I didn't know about beer bottles with twist tops. We don't have them in Denmark, you need a cap opener
At a party in Singapore some Australian friends where in the other boat, they didn't know of beer bottles without twist tops. They were hurting themselves, cutting their hands trying in vain to twist off the unyielding cap. They had brought the beers but had not realised that in order to access the amber fluid* inside, you need a tool. Being a Dane I knew all about the art of freestyle beer bottle opening. With two bottles you can use them to open each other by holding one of the bottles around the neck and use the other one as a lever against your fingers. Once the first cap is off you can replace it and use that bottle to open the other one in the same way.
This of course is only child's play, Danes will brag that they can open a beer with a page from a newspaper or a wet hot dog bun.
The newspaper method:
Fold the page about 1 cm (about half an inch) from the bottom. Fold that over tightly again, again, again, again, again and again until you have made a stick. Then fold that over in the middle.
Grab a beer bottle around the neck, use the newspaper stick as a lever and push it up against the cap using your fingers, around the neck of the bottle, as leverage.
The wet hot dog bun method:
Take a hot dog bun, soak it in water, put it in the freezer for a couple of hours and then open the beer as you would with a newspaper.
*If you find a beer bottle filled with amber liquid on the road, while walking home from a party, do not assume that it actually is beer! (see also: yellow snow).