Dynamic location based desktop on your Mac with Satellite Eyes
This post was published in 2012 and is kept here for reference. It may contain information that's outdated or inaccurate. All external links and references have been updated to point to archived versions on archive.org where possible.
I came across this awesome application today, it sets your wallpaper to a satellite view of your current location. The application features a number of rendering mode, and full support for multiple monitors.

Satellite Eyes is a simple Mac app that automatically changes your desktop wallpaper to the satellite view of where you are, right now.
The app sits quietly in the menu bar at the top of your screen. Pull your laptop out somewhere new, and your desktop will automatically change to the view from overhead.

Truly awesome stuff.
This post is also available in plain text
GitHub API rate limit exceeded. Comments available again at