A couple of my friends and I were introduced to this workout by our A.D. We've been plugging it out a couple times a week, one of the harder sets I've ever done.
http://www.menshealth.com/mhlists/high-intensity-circuit-routine/
click the next button to see the 10 steps.
10 Steps, each for 1 minute constant reps, with 15 second breaks inbetween.