Get the video of the recent scuffle between two band leaders at
http://www.azpunk.com/ (11mb MPEG).
This is how a person who has hit before and is intent on hitting you, is really going to hit you.
I think videos like these are a good reminder to take some time to practice yokomen attacks and techniques at high speed and really DO try to "clock" nage.
If you never practice at high speed, an average guy like this will floor you in 0.5 seconds.
An interesting detail about this video is how the other guy raised his arm to block, but he didn't move his body, and the punch, driven by a couple of hundred pounds of inertia-powered weight, went right through the block, connecting to his head.
EDIT: someone made an animated .GIF out of this; it's shorter and plays slower than the actual video.
