For years, my browser-of-choice has been Flock, the social media browser built on Firefox. Last month I switched my browser to Firefox 3.5 with the Yoono plug-in to see how it compared w/ Flock, and to learn what using a 'more standard' browser experience felt like. Aside from using all the same plugins and addons as Firefox, the experience was very similar.
But I couldn't get comfortable with using Yoono. It's UI feels disruptive, cluttered, and less useful than Flock's built-in social media enabling features. Now that Flock has added more functionality for Twitter (easy re-tweets, replies, and direct-messages) and integrated Facebook chat into the chrome (so you don't have to be on a Facebook page to access it), I've switched back. I've even explored the "My World" page built into Flock. With just a few simple customizations, I was able to reproduce the same functionality as TweetDeck, which can now be removed (right after I un-instill Firefox).
Way to go Flock! Be sure to check out it's new version 2.5.1 available for all platforms