Flock 2.5 has been released, and keeping with it’s “be social” mantra it introduces a few significant features for hardcore Facebook users. First, you get a native Facebook chat client that resides in the status bar where you can exchange messages and share links by simply dragging content to the widget. Also for Facebook fans, you can automatically notify your actions like posting pictures with Flock’s Photo Uploader, adding a blog entry, or contacting MySpace or Twitter users via the People sidebar.

For better Twitter integration, it now features replies, mentions, and direct messages in the sidebar, and also adds a widget to perform searches on Twitter.

Flock is based on Firefox 3.0.x code base and integrates with along lists of social web services including Facebook, Yahoo! Mail, Gmail, Twitter, MySpace, Bebo, digg, Flickr, Blogger, Picasa, Typepad, and a few others.

Flock 2.5 is available for Windows, Linux and Mac OS X.