VS 2005 vs. Firefox
Thanks to Don for pointing this one out, I bet Sara will blog about this in no time too... Since Visual Studio 2005 uses tabs for managing all the different files one would edit, one can naturally apply to browsing the web. Personally, I don't see this as a new way to browse the web, but the focus on making the tabbed interface pervasive and intuitive in VS 2005 is really awesome. As an extra, the middle-click really is well supported, including one of my favorites, which is the ability to close tabs that way.