Before you jump down my throat, this is not sexual. Wet nuts are an ice cream topping, and a damn fine one at that. Waitresses in diners will sometimes ask, "Ya want wet nuts on that, hon?"
Wet nuts are, and are sometimes marketed as, walnuts in syrup. Imagine mixing chopped walnuts into very thick sugar syrup. That's almost what wet nuts are like.
I've noticed lately that lots of people have never heard of wet nuts. Through informal surveys and web searches, I've deduced that wet nuts are a New York / New Jersey phenomenon that enjoy limited popularity elsewhere in the United States. I am unaware of their use in other parts of the world.
In any case, everyone should try wet nuts at least once in his life; they really make a sundae. They can be ordered online (in somewhat large quantities) from Smucker's at http://www.smucker.com.
Update, July 2, 2001: I found wet nuts in Massachusetts! I was shopping for dinner at Star Market when I walked past the end of the ice cream aisle, where they keep the toppings. There, on the bottom shelf, with a little yellow "sale" tag were about 35 jars of Smucker's wet nuts. Of course, I bought one. The joy! Cambridge has finally come out of the dark ages.