from what i know of currency trading, ou relaly need to know your **** and have huge set of balls.
its high risk and you need to move signiican;t amount of money to make profits. YOu re generally exploiting very very small differences in price but if you are trading enough $ the small raise or drop can net some good returns.
a friend of mine is doign bond arbitraige (spelling???) out in cali and making pretty good returns. They exploit the historical gap trading between the 5 and 10 year treasury notes. Its fully model based trading and he's been claiming that te risks score (i forget teh name of teh scale) i slower tan teh sp500 (if say you were trading a tracking stock of it)
he's making decent money for people. I think you gotta start out with 25k though