Just noticed that the Flock browser team has released v1.0 this month. For those of you who haven't come across it before, Flock is built on the Mozilla engine but integrates many of the popular Web 2.0 community sites into its UI. It's currently aware of Facebook, Flickr, Twitter, YouTube, Photobucket, Piczo, delicious and Magnolia, and once you've made it aware of your account will pull down your friend list and let you upload photos, videos, save bookmarks and so on from right inside the browser.
It also has a live writer-like blog post app built-in which can access and send to any blog with a MetaWeblog API endpoint. It also supports Really Simple Discovery too so if you are self-hosting a blog engine rather than using Blogger, Blogsome, LiveJournal, Typepad, Wordpress or Xanga, and that engine (such as dasBlog or SubText) uses RSD, it will set itself up without any fuss. OK, so Live Writer beats it hands down for functionality, but the fact it's built into the browser means one less thing to install. And its supports the majority of firefox plug-ins as well. Those that use a sidebar tend to have a problem as the Flock sidebar is a bit different from that in Firefox.
Flock really has come a long way since I randomly downloaded it at v0.2, and its great to see how much it has improved. The community forums on flock.com include some areas to submit bugs and request integration into other social apps. Picasa and Tumblr look to be favourites at the moment. If you use even just one of these sites, do try out Flock - it's really quite nice.
Now if only the Songbird team would get to v1.0, I'd be pleased as punch.