Grouping Similar Taskbar Items
I think this is one of the best new features of XP. In the past, if you opened three or four Word documents simultaneously each one had a separate button on the taskbar. It didn’t take many open documents to fill the taskbar and shrink the buttons so they were unreadable. No more
By default, Windows XP groups similar items on one button. For example, if you have three Word documents open, you'll see an Explorer item with the number 3 on it. Click it to see a pop-up list of those windows, then select the one you want.
Even better than the grouping, right click on the button and you can close the entire grouping with one click. No more closing individual windows or involving the shift key before closing the most recently opened document.
If you prefer, Windows XP will display all open windows separately on the Taskbar. Right click a blank area of the Taskbar and select Properties. Under Taskbar Properties, deselect Group Similar Taskbar Buttons, then click OK.

- srikanth dhanwada