The new Sidebar feature in Windows Vista provides quick visibility and access to virtually any type of information or resource. The icons that occupy the Sidebar are called "Gadgets" and can be programmed to display any kind of information update relevant for your application or device.
Towards the audio & music creation world, gadgets can be valuable tools for referencing status, levels, or processing activity from an application, a plug-in, or the activities on a connected device. They can help your customers maintain visibility of key aspects of their creation process in a very simple, straight-forward manner.
Microsoft Gadget Center --> http://microsoftgadgets.com
MSDN Gadget Development Overview --> http://msdn2.microsoft.com/en-us/library/ms723694.aspx