QTTabBar is an extension that gives Windows Explorer windows a tab bar (similar to Firefox/IE Tabs). Rather than using a separate program that displays multiple views, you can keep on using your Windows Explorer! This is very useful when dealing with multiple folders since you can have them all in the same window and switching to them is easy.
There is some tweaking you will need to do to get it to display. Once you install it and log off, go to Internet Explorer. Right click the favorites bar and select "QT TabBar" and "QT Tab Standard Buttons". Once these are visible in your Internet Explorer, they will be visible in Windows Explorer. QTTabBar is freeware and is officially compatible with Windows XP and Windows Vista. I have personally tested it on two Windows 2003 Server boxes and it works fine with no problems.