Here's what I did today:
20 Prisoner Squats
20 Forward Lunges
15 Close-Grip Pushups
You are supposed to repeat that twice with no rest between circuits and finish in 15 minutes or less. Not resting in between the circuits is brutal and really pushes your cardiovascular system to supply blood to your muscles. Again, I had trouble with the chin-ups, but after a lot of push-ups, who wouldn't?
I found the trick was the break them up into smaller chunks. I was reading in Men's Health that it was better to fire off a couple of reps, do another exercise, and then come back to the chin-ups to do some more reps. Keep repeating that until you have finished the set. It said that you would get more reps in than if you were doing them all at once. I didn't follow this exact method, but I did break them up, especially on the second time through the Bodyweight 100.
It felt really good to advance onto the next level and I hope to keep it up.