There’s PushUpTheWeb, encouraging non-geeks to upgrade their browsers, improving their their internet experience:
Pushup is an effort to push the web forward by helping users upgrade their outdated browsers. Give your users a better web experience today by installing Pushup on your domain!
And then there’s OneHundredPushUps, encouraging geeks to get fitter, stronger, improving their physique:
If you’re serious about increasing your strength, follow this six week training program and you’ll soon be on your way to completing 100 consecutive push ups!
Lots of wikis and twitter post popping up with people’s results…
EDIT:
And then there’s the push-up craze in China:
“Doing push-ups” became a way for people to vent their anger over the incident and express their disgust at attempts to censor reports and stifle discussion about it on the internet.