Konfabulator for Windows!
I spend my days on the command line prompt or in Visual Studio .NET full screen . Konfabulator looks just gorgeous so I guess I'll have to change my ways and write a command line widget whenever it is released for Windows.
The format for these Widgets is completely open and easy to learn so creating your own Widgets is an extremely easy task.
For the "skinning" crowd, Konfabulator is a dream come true. You can easily change the look, feel, layout, even functionality of a Widget so that it matches your lifestyle, your desktop, or the pants or skirt you have on that day.