I took my "initial test" for the 100 push-up challenge today. Did pretty well, I think. From having stopped training a month ago, I did 22 good-form push-ups without stopping. It let me skip to week three. yay me.
I start tomorrow with Day 1, so we'll see how this goes. In 4 weeks, I should be able to do 100 push-ups in one go.
Here's a link to the website. http://hundredpushups.com/about.html