The WP7 platform has native support for static splash screens. In the following post, I’ll show you how just how easy it is:
- Create an image of size 480 x 800 in your favorite image editor.
- Save the image as a JPEG. At the moment it looks like the file type must be a JPEG to work.
- Include the image in your solution and set the Build Action as Content.
- Run the application and TaaDaa! The splash screen will display for a brief period while the application loads.

I've also posted a video tutorial of this if you would like to see the splash screen in action.