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 +
@ @@@@ | 4 20:56:20
@@@@@@@ | First Quarter -
@@@@@@@ | 3 5:28:34
@@@@ o /
. |
o . /
. /
. .-. /'
`-' /
. .-'
.-'
.--'
---'