The Mythbusters chilled some warm beer pretty quickly in an ice/saltwater bath. I have done that on several occasions. It works in 15-20 min. If you can't entertain your thirsty friends with 15-20 min of conversation - then maybe you should take a toastmasters class, or find some more patient friends.
If money is no object - they proved that you can do the same in a minute or two with a CO2 fire extinguisher.
Mylo