Ubuntu 11.10 is out today! Go download it. OR if you're still on the fence; pondering whether or not you should try dual booting it on your Mac or Windows system - read on.
Virtual Desktops are insanely cool
Out of the box, Virtual Desktops are perhaps the most impressive ‘wow' feature of Ubuntu. And not only do they look cool, but they‘re a tremendous boost for productivity. Its like having an array of dual, triple, or quad monitors (or as many monitors as you want) on a single screen. It exponentially increases the amount of program windows you can comfortably have open at a single time. And once you start using them - you won't ever want to go back to the single desktop paradigm of Mac or Windows.

Above: 6x6 virtual desktops. CTRL + Super key zooms out to this ‘macro view' where you can click and drag any window to different desktops. Or simply use CTRL + arrow keys to cycle one at a time.