Tabs controls have become a very common user interface feature in both Windows and Web applications, and its not surprising. They provide a way to reuse screen real-estate in an easy-to-understand and easy-to-navigate way.
However, ASP.NET 2.0 doesn't provide a tab control. Instead, it provides something even better: the MultiView. A MultiView is essentially a non-visual control that provides a pallette where you can drop several View controls. A View control is another non-visual control where you can place your user interface controls. Think of a MultiView as the tab control and the Views as tabs within it. The difference is that there's no built-in way to switch from one View to another. You can create your own "tabs" using command buttons or use whatever user interface element fits your design.
In this video, Bill Hatfield demonstrates how to add a MultiView to a page and switch among its Views using command buttons to simulate tabs.