One continual disappointment with Windows is the lack of built-in support for multiple desktops. Linux has had it for years. Sure, Windows Vista introduced the Win+Tab window switching, which is pretty, but really not all that practical. What I really wanted was multiple desktop support.
Recently, a friend and colleague turned me onto Windows Pager. It's a small, free application that doesn't require installation. I've been using it for a couple of weeks now and I absolutely love it. I had my doubts at first, but it's been rock solid (knock on wood).
Windows Pager gives you (by default) 4 desktops. They appear on the task bar and work pretty much exactly how I wanted. It's quick and easy to switch between desktops by either clicking on the desktop preview or using a hot key combination.
I put all of my work-related windows on one desktop, all of my personal windows on another desktop, my music (e.g.: Pandora) on a third desktop and then I use the fourth desktop for anything that doesn't fit on the other three.
I really love Windows Pager. It's free, there's no install and it works beautifully.