Tailgating is both an art and a science here in the South, where we really know how to do it right. However, that doesn't mean we're beyond accepting a few tips every now and then.
One of the classic dilemmas of tailgating is how to get your beverages from lukewarm to ice cold in the fastest way possible. Fortunately, the MythBusters tackled this one a couple years ago. The absolute fastest way to do it is to empty a carbon dioxide fire extinguisher into your cooler, but that's expensive and impractical. Side note: if you do try this (and you really shouldn't), make sure you don't use a chemical extinguisher.
Among the safe remedies they tried, the most effective method was putting the drinks in a cooler filled with icy salt water. The salt lowers the freezing point of the water, allowing it to go below the normal freezing point of 32 degrees Fahrenheit. At a frosty 24 degrees F, the icy salt water got their test beer down from 68 degrees, their room temperature, down to just under 36 degrees F in only five minutes.
If you should use this tactic to chill down a freshly-bought emergency six (or 12 or 24 or 30) pack, be sure that you don't forget about it. Just because the ice water stays liquid at that temperature, it doesn't mean your beer will.