Yet another interesting, useless thing you can do: if you set the
epoch for the grids to be 'D' (i.e., epoch of date), then set up animation
(in "proper motion" mode) with a step size of a few hundred years, and
start animating, you can watch the pole drift due to precession. Let
it go long enough, and the pole goes past Vega, then curves back
and goes by Polaris again.

Unfortunately, the IAU algorithm for precession begins to break down
after that, and around the year 30000, Guide tells you that the earth's
pole points through the ecliptic, much as that of Uranus does now.
Look forward to some really extreme seasonal changes in weather
right around then.

Paul, about comet updates: comets are being discovered at a
fearsome rate these days, but most are not especially impressive.
You may just want to visit the MPC's "Recent IAUCs" page at

http://cfa-www.harvard.edu/iauc/RecentIAUCs.html

which will announce new comets. (Be warned that the announcements
are withheld from all persons except subscribers for about two weeks.)

-- Bill