Usability: Launching applications There is no more iconic visual symbol for Mac OS X than the dock, that strip at the bottom of the screen where frequently used applications live. It's easy to forget that you can launch most programs from the applications folder, but good to remember before your dock becomes hopelessly overcrowded. Snow Leopard didn't make significant changes to the dock, so users accustomed to the Leopard way of doing things should be comfortable with Snow Leopard's as well.
Windows 7, on the other hand, makes significant changes to the Windows task bar. It's now possible to pin applications to the task bar to make it far more Mac-like. Further, Windows 7 improves on the Mac model by allowing you to pin folders to the task bar, as well. The Windows 7 task bar can also be moved around the screen, appearing at the bottom, top, or either side, though most users will find it easier to let it sit at the bottom, where it's always been.
Verdict: The ability to pin folders is a genuine improvement to the Windows task bar, especially when your work requires you to constantly refer back to the same set of files. Advantage: Windows 7.
Usability: Managing windows One of the more noticeable functions of Windows Aero is the "glass" view of the desktop. When the cursor hovers over a small bar in the lower-right corner of the screen, all the active windows turn transparent, allowing you to see the desktop underneath. A variation on this comes when you hover over an application on the taskbar, to bring up a thumbnail of the application screen (or rows of thumbnails, if the app has multiple windows open), then hover over the thumbnail; the application's window becomes active while all other windows become transparent. The visual effect is pretty cool, even if the functionality isn't required in every situation.
The Snow Leopard equivalent comes when you click and hold on a dock icon that represents an application that is running. A shrunken application window appears over a darkened desktop, and the application can be chosen with a single click. The Snow Leopard representation comes forward regardless of which Spaces desktop the application is running within, so it's a fast way to jump between the various desktops. Snow Leopard can also let you see all of the running applications in small, side-by-side windows, so it's easy to choose which you should hop to next.
Verdict: While the Windows 7 application and desktop view is graphically richer, the Snow Leopard method is more fully integrated within the rest of the user interface. By a narrow margin, the advantage goes to Snow Leopard.