In yesterday's New York Times, Mark Bittman says the following:

"There was a time when the appearance of the first ripe tomatoes would have inspired me to make the southern Italian sauce of raw tomatoes, basil, garlic and olive oil. These days, I turn to a Mexican-style salsa fresca: tomatoes, white onion, chili and loads of cilantro and lime. The differences in the ingredient lists are minimal, the preparation is identical, and each result is linked to its parent cuisine.

The Mexican version is lighter and brighter, I think, and seems a tad more versatile (the Italian salsa is used primarily on pasta). Both stretch the definition of sauce. Once, you would have called these preparations salads: a sauce was cooked, a sauce was smooth, a sauce was usually complicated. Fortunately, Americans' horizons have expanded, and we routinely throw fresh things like this together in 10 minutes".

Of course, I disagree. I believe that the sugo crudo I mention in my essay The Menu of a Harried Student is much superior to using fresh tomatoes in a Mexican salsa. But that might be because I'm terribly obsessed with good mozarella, and will take any opportunity to stuff it into a dish. Still, what I would say is that sugo crudo is a sauce, and salsa a sort of salad, or condiment. And that's without taking anything away from good salsa.