Second Life Mesh Physics Example
Just like weight painting or skinning in Blender, I have to say that physics in Second Life utterly confuses me. I know what it is, why it is important, but is not sure why you really need it. But then again, must of my buildings are created the old fashioned way via parts. Invisible prims still work well for me for collision surfaces. Not that I haven't tried to understand physics better, it just hasn't clicked yet.
Haven has created a short video that might be helpful in your quest for physic!
Second Life Mesh Physics Example-Haven Ditko