For a handful of sites where users enjoy passing recreational time, Facebook refers more traffic than does search giant Google.

Such sites include CafeMom, Evite, video site Tagged.com, Twitter, and gossip sites PerezHilton.com and Dlisted. Advertising Age called the trend “surprising,” given that web users go to Google to work out “where to go next;” Facebook, in contrast, is more like an online space to loiter.

The social network generates slightly over one-third of Google’s unique visitors (50 million from the U.S. versus 149 million in January, according to comScore).

For its part, PerezHilton received 8.7% of visitors from Facebook, compared with 7.6% from Google (Hitwise), in 2009. AdAge surmises this is mainly because gossip sites are places where users spend a lot of time. But the same did not hold true for another popular gossip site, T.M.Z., which drew 12.2% of traffic from Google, versus 3.8% from Facebook.

Apropos to the other sites: CafeMom has a Facebook Fan page. And Twitter users increasingly favor syncing their tweets with the Facebook news feed, which drives traffic back to Twitter.com.

Facebook has also become a de facto space for sharing links, videos, music and other clips with friends, so it stands to reason that media hosts — such as Tagged.com — enjoy a growing amount of referral traffic.