Some months ago Newsweek published a short article about the different names other countries gave to the symbol ‘@’.
I have forgotten most words but I remember that some of them were quite curious. I am not sure but I think that the Chinese or the Russian called it ‘the mouse’. Actually, if I try, I can see a long tail and a small body on it.
As Hyla wrote, we in Spain call it “arroba” and nobody knows who named it this way. “Arroba” is an old weight measure scarcely used today, I remember my grandfather using it referring to pigs. Some years ago a few humorists started calling it “algarroba” (carob pod) -BTW, a common feed for pigs- and now, what started as a joke, is used by a considerable number of people.
Regarding ‘#’ people try to avoid referring to it because nobody knows exactly how to call it. The most popular word is “almohadillita” (small cushion) but some people say “libra” (pound) or “chirobita” (small hump) or “rejillita” (small grate).
It would be interesting knowing how other cultures refer to those symbols.

Juan Maria.