Enterprise microblogging platform, Yammer, has branched into more of a Facebook-style social network. It was only a matter of time... All the kids are doing it (I'm thinking Salesforce Chatter, but I'm sure there's lots more).

The new Yammer allows employees to share files, post messages, share links, do polls and promote events, but also build your own person profile and post status updates a la Facebook. It also integrates with Twitter and email and it uses analytics to help businesses track engagement in the network.

Like it! And it's still free!