One of the lesser known – but very handy – features of Windows XP is the ability to select multiple separate running applications in the taskbar as a group, then using the right-click context menu to do things you more or less can’t do anywhere else.

To select running apps in the taskbar, you click the first one so it’s "indented", then hold down CTRL and left click the others you also want to select. After that, you can right-click any one of them and get your context menu.

It looks like this:

From here you can do the following:

• Cascade – Resizes windows of selected applications to cascade on screen.
• Tile Horizontally – Resizes windows and "stacks" them one on top of the other.
• Tile Vertically – Resizes windows and puts them in "columns".
• Minimize Group – Sends all apps selected to the taskbar
• Close Group – Will close all selected apps

You will find these features most useful when you want to group apps that "relate" to each other but are inherently separate. For example, if you have open Firefox, Mozilla Thunderbird and another Firefox with an RSS reader page in it, you can group these, then tile horizontal or vertical, then when done just minimize the group.