Courtesy of Chris Shugart of T-nation in this article:

The Texas Push-Up Challenge

Here’s how it works:

1. Begin in a standing position.
2. Drop to a push-up position and do one push-up.
3. Stand back up quickly.
4. Drop back down and do two push-ups.
5. Stand back up.
6. Drop back down and do three push-ups, then stand back up.
7. Repeat this pattern until you do 10 reps on the last set of push-ups.

So, you’ll end up doing a total of 55 push-ups, standing up between sets, and trying not to rest. Or barf.

The Challenge

Goal #1: Just try to finish all the sets, ya wimp. If you do, then congratulations, you’re adequate. Whoopie.
Goal #2: Finish all the sets in under two minutes. Do that and you can brag. A little.
Goal #3: Now it gets personal. From this point on, try to beat your previous time. Or, get a few buddies together and see who finishes first.

Tips and Guidelines

1. Use a full range of motion on the push-ups. None of that halfway horsedoody.
2. Push-up bars are fine if you want to use them.
3. Most people “hit a wall” around the 7th or 8th set. So don’t get too cocky when set #6 feels easy. Pride comes before the fall, hoss.
4. If you have to rest more than a few seconds between sets, you fail. Try again another time.
5. Take the Texas Push-Up Challenge on an off day, or do it first thing on the day you train chest or upper body. You may want to truncate your chest workout a bit though since you’ll be doing 55 intense reps of push-ups at the beginning of your normal workout.