I read a story earlier this year about a retired minister from Orkney who had worked on this. He had donated his idea to the RAF, who were going to experiment with it!
He had patented an idea to modify tyres during the forming process, to include cups that were an integral part of the side wall. These cups would then cause the wheel to rotate whenever they were exposed to the airflow.
I'm almost certain I read the story in the Times, but can't find it in their search engine.
Sounded like a pretty good idea to me.