I'm a left-handed ex-LEO who trained on a "regular" .38 revolver back in the day.
As was mentioned, the forefinger of the shooting hand can be used to actuate the cylinder release on some revolvers. There are three types of releases in common use.
One is the "push forward" release, used on S&W, Taurus, Rossi, and Charter Arms revolvers. The release is pushed forward, toward the cylinder and barrel. I find this to be the most difficult of the three.
The second is the "pull-back", found on Colt revolvers. The latch is drawn back toward the rear frame, and can sometimes be done so with the shooter's thumb as well.
For me, the easiest one by far, useable by the thumb (which is typically stronger), is the "press-through" button found on Ruger revolvers. This is simply pushed inward, as if trying to push it through to the other side of the gun, and can be done with the side of the shooter's thumb.
Personally, I'm so used to "normal" revolvers that, were I to be handed a SouthPaw (Charter Arms product), I'd be at a near-loss as to what to do with it.
Quick reloading of a "normal" revolver by a LH-ed shooter isn't hard, and can be taken down to mere tenths of a second longer than by a RH-ed one. I had ot develop my own technique, which has been "discovered" by countless others as well independent of me. I'll try to find a thread on here I'm thinking of regarding it.
EDIT: Here it is. Check out posts nine and twelve regarding my experiences.
http://www.thehighroad.org/showthre...ight=rapid+reload++left++revolver#post8954341