I'm posting this from Flock, the latest Web 2.0 app that is creating quite a buzz today. If you haven't heard about it, Flock is a browser based on the open source Mozilla code base that integrates with del.icio.us, flickr, Blogger, Wordpress, Typepad and soon, many more social web services.
Some of the features I have discovered so far are that favourites automatically sync with del.icio.us, tags can be added to favourites, RSS feeds based on sites, tags or favourites can be aggregated within the browser and blog posting is also integrated within the browser.
Of course, there are already Firefox extensions which can do all this, but they way Flock has integrated these services does feel nice, and the UI is quite smooth. Already some of the popular Firefox extensions, such as the Web Developer Toolbar, work in Flock.
It's still in beta, at version 0.48 at the moment, but from my perpsective it certainly looks very promising. Having all these tools and services in the one environment helps with productivity, blogging, tagging and all the other things that web geeks like to do. Oh, and it's also seems to load pages faster than Firefox, but that may just be my system..