This is David Nebenzahl's new joint. I think I misunderstood his
directions (posted as a link in rec.woodworking). I tried making all
three members the same as shown in picture one, but the third member
would not fit (picture two). I made the third member as shown in
pictures three and four. In picture five you can see it makes up.

Don't look too close at the joint, it was made in a hurry to see if I
could make it. I intend to use it in a project.