Via Andrew McAfee‘s blog, WorkBook, from WorkLight is a “corporate overlay” for Facebook. It somehow let’s your company’s users continue to use Facebook, but in a secure way, and incorporates data sources from within the firewall.

Here’s Andrew’s post.

I think I need to see more than a screenshot before I decide how interesting this is. It’s not clear to me yet exactly how WorkBook adds a security layer, how it connects to enterprise data sources, how those are made available, etc.
Also, I understand the security concerns raised when a company says, “Let’s just use the public instance of Facebook for our intranet,” but the specific constraint one of Andrew’s commenters proposed which is that “the corporate admin  [should] manage who they can be friends with” seems ridiculous. An internal social networking site in which people are not free to make connections to whomever they want seems doomed to failure.