well...as far as I know so far, you make mathematical models for financial instruments (e.g. superannuation, insurance, etc) that helps others to optimise their finance and use of resources
OR (well...both I guess
) you become an analyst/advisor and basically give advice to loads of stakeholders (companies, government, individuals).
you've gotta be pretty good to do it (and you have to 'love' maths apparently). had a guest speaker today, and she was saying that there's like 2600 members of the institute of actuaries australia, of which only half or so are active (the rest are students, etc).
hmm...yea...that's all I can think of at the moment.