Jews and seltzer

[scottp]

I heard a Lou Holtz joke about three sailors who survived a shipwreck and drifted in a lifeboat for many days with no fresh water. When they were found, the rescuers insisted on taking down their names and hometowns before even providing a drink of water.
The first one gives his name and hometown, and immediately demands, "Water... water!"
The second gives his name and hometown, and cries out, "Water, water!"
The third one gives a Jewish name, and is from New York City, and he begs for "Seltzer, seltzer!"
So I googled "jewish" + "seltzer." There are 1.3 million hits. Seems like maybe a million have to do with Seltzer as a last name, but that leaves over 300,000 concerning seltzer water.
This was one of the interesting items: http://www.nmajh.org/weblog/cur/index.htm
And now I know what "two cents plain" means.