In the US, it's usually referred to as the pound sign. We don't have to worry about the British pound.

Thanks for the links, JazzO - I did a search, but did not go back far enough to find those references. Since Britain is still the largest single source of foreign investment in the US, I'm not sure whether the last sentence I quoted is entirely accurate.

As to the currency/weight dilemma - I was born 4 months after NZ switched from pounds to dollars, and we have always used lb. as the abbreviation for pounds (avoirdupois or troy, it matters not) as opposed to £sd, so we never "tripped" over that one. I would be interested to hear from anyone who knows the history of "pound" and "hash" for # - I wouldn't know where to begin to LIU.