Here's some news that recently came out:

http://www.newscientist.com/article.ns?id=dn7867

http://abc.net.au/science/news/stories/s1439827.htm

Apparently, soundwaves can help airflow stay near the wing and increase
lift. This can help smaller aircraft to avoid stalling at lower
airspeeds. Is this a technology that could be usefully applied to
existing small aircraft? Or would it require some totally new design
thinking?