This is pretty neat. Tim James, over at EMC Consulting, has provided a detailed how to (if you will) of bringing depth to a 2D map to Windows Phone 7. Namely, wrapping a map around a 3D sphere. Tim also explains how building a 3D map using a flat image can show signs of distortion among and top and bottom halves, while the equatorial area covers much more surface space. All of which could give added dimension to apps.
On a side note, while reading the article I'm heavily reminded of Street Slide, except this isn't improving street view and making it appear as a more constant 3D 'walkthrough'. Check out the video below for the app Stars3D (opens Zune), which is really impressive and runs along the same idea but instead we're inside the sphere looking out.
Source: EMC Consulting