Here's another, the Lockheed ring wing. Found a nice documentary on it too
What Happened To Ring Wing Planes? - YouTube Too much drag and cross-wind interference though. To my recollection, I sure I remember the US and Australia working on a lifting body airliner that also had very high speed to be anywhere in a few hours. I haven't found that again. Everything seems to talk of normal speed, other than the UK Sabre rocket/jet engine. Any ideas?