I used to do these and loved them! Basically you do 8 reps for 8 sets while resting only for 1minute at a time. Each week you shave off 5-10seconds off your rest periods, for as many sets. These were intense as all hell.
I think I am going to start training assistance work in this fashion for awhile just to get it done fast and feel like I did something.
Crazy 8's was a training method used by Vince "The Iron Guru" Gironda. I read this a while ago in a free magazine I got from vitamin shoppe a few odd years ago. Here is the article.
Muscle & Body Magazine