I guess a single network-wide message doesn't really outdo Visa in terms of sheer effort, but it's certainly a testament to:
a) how incredibly important Michael Phelps's successful endeavour is (indeed, must be) to 16.91 percent of the US social networking population, if not the online gab-o-sphere at large.
b) how incredibly important the Olympics are (and indeed, must be) to everyone, ever (is it possible the weak economy helps? You know, like how the movie industry boomed during the Great Depression?)
c) both a) and b)
Clicked on the Michael Phelps Facebook page just for kicks. Heeeeey, diggin' the Speedo shot. Observe Olympic tattoo on right (that's your left) pelvic bone: