Phoon displays the phase of the moon, either currently or at a specified date / time. Unlike other such programs, which just tell you how long since first quarter or something like that, phoon shows you the phase with a cute little picture. You can vary the size of the picture with the -l flag, but only some sizes have pictures defined - other sizes use @'s.
Sample output (HTMLized via texttohtml):
-------.
. . `--.
. . `-.
. @@@@@ `-.
@@@@@@@ . \
@@@@@@@ . \.
@@@@@@@ O \
@@@@@@@@@@ @@@ \
@@@@@@@@@@@@@ o @@@@|
@@@@@@@@@@@@ @@ \ New Moon +
@@@@@@@@ @@@@ | 6 22:01:03
. @@ . @@@@@@@ | First Quarter -
-. @@@ @@@@@@@ | 0 7:23:23
-' . @@@@ @@@@ o /
@@ . |
. O . o . /
. . /
. . .-. /'
`-' /
o O . .-'
. .-'
. .--'
-------'