In your response to how salted ice can freeze ice cream, I feel it is misleading to say that "the water temperature drops. . . " Is the ice not as cold as it is ever going to get when you put it in the ice cream maker? Salt just allows the water to melt from the ice sooner (colder–or before it has warmed up to a less useful temperature for making ice cream). I don’t feel you answered the question–thousands of teeming masses are going around thinking that salt somehow is a cooling agent!
eric
To melt ice, you need energy to break the bonds between water molecules. This is true even if the ice is melting because of adding salt. When the salt is added, the ice melts, with the energy coming from the heat in the ice. This resultis in the ice-salt water mixture becoming colder. So “the water temperature drops. . .” is exactly correct.
ETA: Is this the column?
Yes–but the water on its surface is not. When you sprinkle salt over ice, two things happen: the ice starts to melt, as the effective freezing temperature (at the ice/water/air interface) has dropped; and the water film on its surface rapidly cools, as the system attempts to restore thermal equilibrium.
If the starting temperature of the ice is higher than the melting point at the salt concentration you create, the water can actually become colder than the bulk of the ice, so in a sense it really does act as a cooling agent. It doesn’t actually pull any energy out of the system–the ice will warm up as some of it melts–but for ice-cream-making purposes, we don’t care about the temperature of the ice, and the water dripping off could well be colder than our original freezer temperature.
Welcome to the fun, crazy world of thermodynamics! 
Salt is a cooling agent when added to an ice/water mixture. Think about it - you want to freeze the ice-cream mixture, which has a freezing point lower than that of ordinary water. Just packing ice around it won’t cool it to below freezing point (or actually the triple point of water, 0.01C, I suppose).
But an ice/water/salt mixture will cool to considerably lower than 0C, because the energy taken to melt the ice has to come from somewhere. In theory it can reach as low as -21C.