Here's one for you guys with light airplanes:
Advanced Flight Systems
The airplane had one of those little vanes on the strut called a "Bacon Saver" which was nothing more than a 2" wedge on a card with some red paint in the 'no go' zone.
Because it was mounted on the left strut, it was right in line with my sight as I turned final. I found I looked at that more than the airspeed indicator in the pattern, and certainly while doing the steep turns taking pictures.
But like someone said above, you can't fix stupid. Putting an AOA vane on all airplanes won't stop idiots from killing themselves in airplanes, especially light airplanes, if they try hard enough, they will always find a way!
I tried to find a link for the Bacon Saver, but can't, maybe they are out of business? It was a really low tech, cheap AOA with no electronics required, just bolt it on the strut, but it wouldn't have a place to mount on a low wing airplane, you need the wing strut to mount it on.