Featured Site: The Earth and Moon Viewer
This is an absolutely incredible site. You can look at the Earth from the Moon or the Sun in real-time. You can click on the image and pan anywhere around the globe. You can sit at your computer (as I have once or twice) and watch the sunrise and set. Who needs to go outside?
The imaging is highly configurable. The first thing I do when I click on either of the links above is scroll to the bottom of the page and set the image size to 600 pixels. I find that any larger and the image becomes pixilated.
This site was developed by John Walker, founder of Autodesk, Inc. and co-author of AutoCAD: one serious geek! Here is his home page.