I actually got this from T-nation, but it's a great way to shock your muscles. Me and my buddy did it the other day and I'm still recovering.
100 reps of dips
100 reps of chins
Basically do 10 sets of 10, supersetting both exercises (switch back and forth). Try to make it to 200! Once you get good, you can time yourself and try to beat that time.
There were a few instances I would do 7 chins, 10 dips, then go back and do 3 more chins. It was HARD. I only made it to about 75 chins and then quit out, I was completely spent. I did manage the 100 dips though.
Anyone who tries this please post feedback.