What about Windows Sidebar in Windows Vista?

Please refer to the following contents
  

In Windows Vista, Sidebar is located on the desktop and contains gadgets, which are customizable mini-programs that display continuously updated information and allow you to perform common tasks without opening a window.
 
About Windows Sidebar and Gadget, please refer to the following contents.

■ About Sidebar

Windows Sidebar is located on the desktop which is used for organizing the gadget tools.
Windows Sidebar can be customized according to usage in a simple form.
Generally it displays on the top of the screen, sometimes it can also be placed in the bottom of the maximized window.

■ About Gadget

You can access the Web Browser, Calculator and Calendar quickly through gadgets.
Windows Vista has internalized gadgets with basic functions and you can use it instantly. 
You can also easily download other accessories from the Online Gadget.