A Simple Pushup Plan
Boy, it doesn't get any simpler than Stew Smith's push-up workout:
On ODD days: Do 200 pushups in as few sets as possible in addition to your regularly scheduled workout of cardio exercises. You can still do upper body workouts on these days if you are already on a program. This is a supplemental 200 pushups using maximum repetition sets (4 x 50, 8 x 25 ... it's your choice how you get to 200).
On EVEN days: Do 200 pushups throughout the day. This can be little sets of ten done every half hour or fifty pushups done four times throughout the day.
RULE: If your maximum is under 50 pushups, do 200 a day. If your maximum is above 75, do 300 pushups a day.
Repeat the ODD/EVEN routine for a total of 10 days. Then take three days off and do NO upper body pushing exercises that work the chest, triceps, and shoulders. Then on day 14, give yourself the pushup test.
He says folks who start at 50 pushups end up at 80 (generally, I'm sure). Pretty nice return on two weeks work.
P.S. I know it sounds like overtraining, but he discusses that in the article.