Two billion iPhone apps have been downloaded from the iTunes app store

""Apple today announced that more than two billion apps have been downloaded from its revolutionary App Store, the largest applications store in the world. There are now more than 85,000 apps available to the more than 50 million iPhone™ and iPod touch® customers worldwide and over 125,000 developers in Apple’s iPhone Developer Program.
“The rate of App Store downloads continues to accelerate with users downloading a staggering two billion apps in just over a year, including more than half a billion apps this quarter alone,” said Steve Jobs, Apple’s CEO. “The App Store has reinvented what you can do with a mobile handheld device, and our users are clearly loving it.”"
Source: Apple press release, 28-9-09
Note - the first one billion downloads took nine months; the second took only five (24th April - 28th September)