Flock — The web browser for you and your friends

What Flock is? In short:

“Flock is a free web browser that makes it easier than ever to share photos, stay up-to-date with news from your favorite sites, and search the Web.”

Longer: Some of the most impressive developments of the so-called web 2.0 movement have now found their way into a mozilla-based browser. Many blog services, bookmark services like del.icio.us and photo sites like flickr.com are supported by the browser so you can work with them seemlessly. A first beta is now available for download on windows, linux and mac.
One might say that you probably can add those functionality to standard firefox through plugins. But nevertheless I think this is worth a try.