If you haven't yet seen the comet PANSTARRS' current pass, take a look at Dan Finnerty's time-lapse video. He captured the comet's flight toward the horizon from Altadena, California, in tandem with the setting moon.
PANSTARRS will continue to be visible in the Northern hemisphere until the end of the month, if you have an unobstructed view to the southwest at twilight. But even if you miss PANSTARRS, there is more comet-viewing on the horizon; ISON will give us a more spectacular light show this fall.
If you're having trouble watching the video, watch at Vimeo.