Recently Ahmad, our test intern, created a WPF weather user control and it came out really nice. Take a look.
The code is available on code plex .. The code also includes a sample which is demo desktop weather gadget using the usercontrol.
The user control provides 2 dependency properties, IsMaximized and ShowMinimizeButton.... The first property decides whether to show the control in a minimal form just as the Vista weather gadget behaves in the sidebar. The second property decides whether to show the minimize button.
In xaml, you need to reference the dll as follows
<y:WeatherReaderUI Minimized="False" HideMinimizeButton="False"/>
The setting dialog is a popup so it comes up on top of your app. The control was created with reusability and extensibility in mind. Currently it connects to the MSN xml feed. Changing the feed requires a slight tweaking in code since the xml tags differ from site to site.
Please do take a look at the code .... 🙂