While it may be legal to carry a gun without a holster, I don't recommend it. The holster keeps the gun where it's supposed to be, protects and covers the trigger area (Safety reasons), plus it's just the responsible way to carry.
Awww, cmon man, you mean it aint safe ta shove the barrel into your crotch like in da movies? Shoot, er well DON'T shoot...not with it pointin' at the boys!