Nevertheless, I'm not as enthusiastic as some about this new Laserlyte gizmo that fits in the gun's rear sight dovetail, and for a couple reasons:
1) I'm assuming it's a two-piece unit; ie, the laser-y bit gets attached after you've drifted in the dovetail itself. Anyone who's seen a rear sight get installed knows why. (If you haven't seen a rear sight installed, here's a hint: It often involves a hammer.) Two-piece objects on carry guns have an uncanny ability to separate themselves into their component parts at the worst possible time, usually after getting dropped in the aforementioned dark parking lot.
2) Any control on the gun necessary for bringing it into action should be operable one-handed from a firing grip. This is why CTC Lasergrips have such an edge over guide-rod lasers in my estimation; you don't have to find a little button in the dark while you're rolling around in a parking lot. But even the guide-rod lasers usually put the activation switch somewhere near where the trigger finger would index on the frame if your booger hook is properly off the bang switch. This Laserlyte thing, on the other hand... I don't know about you, but at no time in my drawstroke is my thumb atop the slide.
It must suck to try and get into the CCW laser game after the good ideas have already been taken...
(H/T to Unc.)