There’s a simple trick that’s been built into Windows forever… hold down the Ctrl key while selecting taskbar buttons and you can select more than one at a time. The benefit is that you don’t have to minimize any other windows in order to tile them (or close them)
Hold down the Ctrl key while clicking on a taskbar button, and then while still holding down the Ctrl key, click on another taskbar button. You’ll notice that they are both selected. (Note that you can click on a button again to deselect it.)
Now that they are both selected, you can right-click on one of the buttons and choose to cascade, stack or show the windows side by side.
I don’t find cascading or stacking very useful, but side-by-side is something I use quite often.
This can be extremely useful when you are trying to look at two windows at once, especially when you’ve got a ton of windows open but only want to tile two of them.
Note: This should work fine in Windows XP even though the screenshots are from Vista.