It's the bane of every beer drinker. You just bought a big ol' case of beer, but it was either unrefrigerated or warmed up on the way home. Drinking room-temperature beer is terrible, but it can take hours to get chilly in the fridge.
Don't worry, my impatient friend. Science has your back. All you need is a bowl, ice and some salt. This video from DaveHax explains how it works:
In just two minutes, you can reduce a room-temperature beer to a chilly 40 F (4.44 C) or so, which is even colder than the recommended serving temperature for most beer.
The science: Salt lowers the freezing point of water, making the ice melt. A 10% salt solution reduces the freezing temperature down to 20 F while 20% brings it down to an especially chilly 2 F. Adding salt to the ice-water mixture thus lowers its freezing point, causing the ice to melt quicker and in the process absorb energy from its surroundings (like your beer). The stirring is a method of forced convection which speeds up thermal equilibrium.
Image Credit: BuzzFeed
Gizmodo's Brent Rose recommends keeping the ice-salt mix soupy rather than full of solid cubes, increasing the surface area in contact with the can. The drawback of the ice-salt method is that you need to keep draining the water and adding more ice if you want to keep chilling more beers. At that point, it's probably easier to just cool one or two and wait the rest out.
Another neat party trick explained by Gizmodo's Brian Brushwood is freezing beers. Take the ones that don't explode, pop the top and give them a good rap on the side. This causes the unfrozen liquid to rapidly supercool, which is fun to watch. We don't recommend this, because there's probably a nonzero chance of the beer violently exploding.