AllFacebook.com is reporting that more than four million Facebook subscribers access the social network from a mobile phone every day - and that's just from the top three mobile Facebook apps.
According to the site's Facebook application statistics, the iPhone is the most common mobile access point, with some 1.64 million active daily users. This is followed by Facebook for BlackBerry with 1.56 million and the generic mobile Facebook app, which has nearly a million daily users.

The actual number of mobile Facebook users is higher, because the site's figures don't include folks accessing the service from Palm devices or others who visit Facebook from their phone without downloading a mobile-specific application.