On NASA's Earth Observatory site, a picture was just posted that's too pretty not to share. It's a plume escaping from the Bezymianny Volcano in Kamchatka on November 25:
Cooool. It was taken by the Earth-observing satellite Terra, using ASTER: the Advanced Spaceborne Thermal Emission and Reflection Radiometer. The image is in false color; the white plume suggests it's mostly steam, and not laden with the usual ash and dust (the brown you see in the image is the shadow of the plume on the terrain).
I highly recommend the Earth Observatory website Image of the Day if you like looking at beautiful imagery of our home planet. And if you have more suggestions for such sites, leave them in the comments below!
Image credit: Robert Simmon, based on data from the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.