Phases of the Moon and Percent of the Moon Illuminated
Pictures, animations, and brief comments.
http://aa.usno.navy.mil/AA/faq/docs/moon_phases.html

Correct Time and Moon Phase
From the atomic clock at the United States Naval Observatory.
http://www.obioncounty.com/News/clock.html

Moonstick Information Site
Describes a slide rule Moon phase calendar accurate over 8000 years into the past or future, and provides other methods of computing astronomical information.
http://www.moonstick.com/

Moon Phases
Information and Perl script to calculate moon phases including phase illumination age distances angular diameter new/full moon calculation
http://search.cpan.org/~brett/Astro-MoonPhase/MoonPhase.pm

Phase of Moon
Displays the phase of the Moon in a browser window, with times of last and next Full Moon and New Moon.
http://www.die.net/moon/

Xphoon
Xphoon sets the X-Windows root window image to a picture of the Moon in its current phase.
http://www.sourceforge.net/projects/xphoon/

The UnMuseum's Ponzo and the Moon
Explains why the Ponzo Illusion makes the Moon appear larger when near the horizon.
http://unmuseum.mus.pa.us/exmoon.htm

Virtual Reality Moon Phase
The United States Naval Observatory (USNO) Moon phase display for the years 1800 through 2199.
http://tycho.usno.navy.mil/vphase.html

Phases of the Moon Exercise
Shows the Moon in eight positions around the Earth to shade in the dark area and the unobservable side.
http://helios.astro.lsa.umich.edu/Course/Labs/moon_phases/moon_phases.html

Saint Paul Public Schools Phase of Moon Test
Twenty-five questions about the Moon's phases and rotation with an answer key, geared to fifth-graders.
http://www.curriculum.spps.org/extended/PDFs/Gr5PDFs/MoonTst.pdf

Lange and S%c3%a1¶hne 1815 Moonphase Watch
Mechanical watch that displays the phase of the Moon, accurate to one day in 1000 years.
http://www.lange-soehne.com/en/02_watches/index_edition_1815mondphase.php

Phase of Moon GIF
A 100 by 100 pixel GIF image of the current Moon phase on a black background, from the United States Naval Observatory. Accessible as a URL for embedding in web pages.
http://tycho.usno.navy.mil/cgi-bin/phase.gif

Telescope: Dating van Gogh's Moonrise
Article identifying the exact date and time of van Gogh's Moonrise painting, based on Moon phase calculations.
http://skyandtelescope.com/aboutsky/pressreleases/article_968_1.asp

Telescope: Greek Marathon Dated from Phase of Moon
Describes how astronomers used phase of Moon calculations and ancient Greek religous festivals to date the original Marathon run.
http://skyandtelescope.com/news/article_1306_1.asp

The Space Place Images of Earth's Moon for the Classroom
NASA Moon images with captions showing different phases, suitable for printing and classroom display.
http://spaceplace.jpl.nasa.gov/en/educators/teachers_moon_images.shtml

How long does each phase of the Moon last?
NASA's Dr. Marc of The Space Place answers questions about Moon phases and the lunar month. Includes GIF animation of the Moon going through its phases.
http://spaceplace.jpl.nasa.gov/en/kids/phonedrmarc/2004_march.shtml

StarChild Moonlight Madness
NASA's Star Child site page that describes the phases of the Moon. Ends with a test to identify the eight Moon phases and their order.
http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/moonlight.html

The Moon: It's Just a Phase It's Going Through
The Astronomical Society of the Pacific's detailed explanations of the Moon's phases, including positions of the Moon in southern and northern hemispheres during its different phases and the times of day each phase is visible.
http://www.astrosociety.org/education/publications/tnl/12/12.html

Moon Phases 5000 Year Catalog
NASA Goddard Spaceflight Center (GSFC) Five Millennia Catalog of the phases of the Moon.
http://sunearth.gsfc.nasa.gov/eclipse/phase/phasecat.html