Beautiful clear images of the Earth can be viewed via NASA. The Gateway to Astronaut Photography of Earth hosts images from different countries. Highlights can be found here or via a clickmap of the Earth.

It also provides easy searching, advanced site searches and educational materials. Urban spreads, pollution, burning off and algae blooms show very clearly.

For those who would like to watch the Earth as a three dimensional model with constantly updated information on their own system, the EarthBrowser software offers weather forecasts in 17,000 places, live hurricane tracking, updated cloud animations, iceberg tracking, hundreds of webcams around the globe and much more. A free demo can be had, but the real thing costs $.