Meteor showers schedule: http://www.learnwhatsup.com/astro/current/meteors.shtml
Heavens above: http://www.heavens-above.com/
See a sky map from your location. Next satellite sightings.
A graphical display of over 500 satellites.
Astrophotography by Russell Croman: http://www.rc-astro.com/
An awesome earth-bound photographer.
NASA/JPL photojournal: http://photojournal.jpl.nasa.gov/jpeg/
A collection of pictures from various space explorers.
Astronomy Picture of the Day: http://antwrp.gsfc.nasa.gov/apod/
Just what it says. But this is the index: http://antwrp.gsfc.nasa.gov/apod/image/
Hubble Heritage Project: http://heritage.stsci.edu/
Best resource for Hubble Images. (IMHO)
Official web site. Lots of info and lots of pictures.
Comets currently visible: http://encke.jpl.nasa.gov/whats_visible.html#00WM1
These sunzabitches don't seem to be interested in updating their site. I'll leave it up here just in case though.
Students for the Exploration and Developement of Space
University of Arizona Lunar and Planetary Laboratory.
Our polar ice caps.
The north pole from space.
A picture from the north pole cam.
The earth at night. Right-click and save for the big version.
Under construction. (ISS).
Skylab. Back in the day.
Aldrin and the flag.
Endeavour cargo bay.
Luna. Or is it Celine?
With Saturn peeking around the corner.
Jupiter and Io from Cassini.
The galactic center.
Hubble ultra deep field image. ~18 billion light years away.
And here's a blow-up. (Middle towards the bottom of above pic).
Zeta Orion region. Horsehead and Orion Nebula.
Great Orion Cloud.
Saturn from Cassini. Click on this image to get the big image, where you can see the moons too.
Moons visible in this image are (clockwise from top right): Enceladus (310 miles across), Mimas (247 miles across), Tethys (659 miles across) and Epimetheus (72 miles across). Epimetheus is dim and appears just above the left edge of the rings. Brightnesses have been exaggerated to aid visibility.
Night on Saturn from Voyager.
Another angle on Voyager 1.
The gold record fastened to Voyager.
Jupiter with the Pioneer plaque.
Sunset through the dust on Mars.
Another sunset on Mars. Or maybe sunrise. I forget which.
Earth and Moon from Mars.
Phobos. One of Mars' moons.
Callisto, Ganymede, Jupiter and Europa from Mars Orbital Surveyor. You will probably have to scroll to the right to see them all.