I like the workout, although I would mix up the push ups, standard, double shoulder width, hands in front, hands close in under the centre of your chest, push-ups with your fingers pointing
towards your toes and "divebomber" pushups like here

http://www.trainforstrength.com/ex-1.shtml

I agree with the previous posts though, I am not sure push-ups will do much for your strength but they are great for endurance.