If you're not interested in the tails, there's also always (random()+random()+random()+random()-2.0)*sqrt(3.) as a cheap (in terms of brain power) Gaussian (s

If you're not interested in the tails, there's also always (random()+random()+random()+random()-2.0)*sqrt(3.) as a cheap (in terms of brain power) Gaussian (sigma=1, mean=0) rough approximation :-)