I've searched the forums and found instances of members using Viridian and Laserlyte lasers on S40s, but Iv'e spent the week going store to store and mounted lasers on my new S40, and they just don't seem to work. To be honest, I haven't tried a Viridian, as I'm trying to keep it small and compact, but I have mounted a Crimson Trace Rail Master (twice) and a Laserlyte Micro (I'm trying to stay compact). Mounted firmly, they both are targeting about 10 inches below the bore line and 2 inches to the left. We made all the elevation adjustments we could and neither sight would move up enough wihtout backing the screw all the way out. Is it possible my rail is not properly machined in line with the barrel of my pistol, or am I missing something else? I was helped by 3 different salesmen who I believe know they're way around firearms and their products as these were firearm stores - not sporting good stores, and they were as confused as I still am. I love the trapezoid sights, and I don't want to change them for night sights, but I want an effective and easy way to aim in dark situations. I think the laser is the way to go, but again, I didn't want to go with the bulk of a Viridian to get it done. Any thoughts would be appreciated. Thanks.