From an otherwise boring letters page on The Register (although I did learn that C# and Db are actually slightly different frequencies, which I never knew before):

Just to let you know, # is also the abbreviation for fracture in medicine ( can't speak for the US though). For example C-Spine # = fracture of the cervical spine ( a broken neck). So the new M$ product C#, accordingly is either paralysed or dead, says Pete W.