"Quick cash" generally means that you'll have to do something you normally wouldn't. After all, if anybody would be willing to do whatever it was that people are paying the 'quick bucks' for, then everybody would be doing it... right?
So, here are a few legal options:
Male dancing (private events or at a bar/club - be this frequented by older women, or if you're really in need of money, men).
Selling plasma (this is the route taken by many inner-city people in need of quick money, as evidenced by the overabundance of these sorts of facilities in lower-income areas)
Medical studies (such as the Pennington Biomedical Research Center... These sorts of things are OK, if you have one near your area, but otherwise you're out of luck)