3 mins skipping 20 push ups 30 sit ups 15 pull ups 50 squats 20 push ups 30 sit ups 15 chin ups
Repeat this circuit 2 more times
Add in short bursts of very high intensity when skipping, use a plastic speed rope, you can get one for a fiver
Vary the sit ups and push ups with different styles eg hands close together\wide apart\incline\between chairs for the push ups and twisting to the sides\V ups for the sit ups
Not a great workout for packing on a serious amount of bulk, but if you want to get considerably stronger while being lean at the same time then give this a try. Add in more reps depending on level of fitness.
I do this about 3 times a week. After stretching, it usually takes me 45 mins to complete. First time I tried it I felt like I was going to throw up halfway through the third circuit but it gets a lot easier :)