<character> "#", ASCII
Common names: number sign; pound; pound sign; hash; sharp; crunch
; hex; INTERCAL
Rare: grid; crosshatch; octothorpe; flash; ITU-T
: square, pig-pen; tictactoe; scratchmark; thud; thump; splat
The pronunciation of "#" as "pound" is common in the US but a bad idea; Commonwealth Hackish
has its own, rather more apposite use of "pound sign" (confusingly, on British keyboards the pound graphic happens to replace "#"; thus Britishers sometimes call "#" on a US-ASCII keyboard "pound", compounding the American error).
The US usage derives from an old-fashioned commercial practice of using a "#" suffix to tag pound weights on bills of lading.
The character is usually pronounced "hash" outside the US.
The name "octothorpe" was made up by a Bell Labs
supervisor, Don Macpherson.
Octothorpe story (http://www.sigtel.com/tel_tech_octothorpe.html).