It would be nice if you could have an option to draw
lines around the screen where the horizon is, 45
degrees up, and maybe the cardinal directions (N, S, E,
W), so the viewer can get a better feel for what area
of the sky they are looking at.
Sample image of Planetarium
It doesn't need to be that in depth -- the version of
Planetarium I have only puts a "SW", "NE", etc at the
bottom of the screen, a line for the horizon, and a
dashed line at 45 degrees up.
I would use this for when I zoom in to see more detail
of the stars -- I get lost when scrolling around in my
Palm, and I lose my feel for how far up the star is or