I have never learned nor heard of this method in solving complex multiplication, maybe it is a secret kept by some elite college. This method made multiplying numbers, even the most complex one look like a walk in a park. So incredible I can't wait to show my children. (Video)
Update: Youtube removed this video, but someone soon put it up again! Kudos! ( Link)
Update: Insight from Dennis,
If this is "invented" by student and shown to teacher, I think it is good. But if this is by teachers, who tries to skip teaching maths and just to show non-mathematical ways, in this case by drawing lines, then I think it is bad.
Update: Third time YouTube removes this video for violation of agreement, me start to think that fingers are NSFW. :D (Video) updated