Negative Camber Doesn't Seem Right

Positive camber is for bias ply's and shouldn't be run with radials, especially modern radials.

Mattax is right on. What you want is the most even tread pattern you can get, as much of the time as possible. But that changes with how the tires are loaded, so you're trying to match your alignment up with the type of driving you do, the roads you drive the most, and the specs of the tires you run.

On my cars I've run as much as -1* of camber without seeing any ill effects on the tread wear. Like everything though that depends on how you're using the car. A car used as exclusively as a commuter with extensive freeway use would show camber wear with less negative camber than a car that's used in more mixed driving. And a car used primarily as a canyon carver or autoX car could run much more negative camber without showing any camber wear effects because of the amount of cornering being done. You could actually see wear from not running enough negative camber if the car is always cornering, just like you would see it from having too much if the car is always freeway driven.