Originally posted by Mr_Ed
You may want to research a family of light planes built in Germany in the 1920's and 30's. The early Klemm's used such a configuration for roll control.
Mr Ed
I did not find anything on the Klemm aircraft, but here is a interesting technical paper from NASA
http://techreports.larc.nasa.gov/ltrs/PDF/tp3258.pdf
It basically coupled conventional ailerons and tiperons. It achieved roll control DEEP into a stall of 70 degrees AoA!!!