A coworker recently turned on to the open source space exploration software Celestia. If Google Earth is the coolest software ever created (it gets my vote), then Celestia is second coolest, and is basically like Google Earth, but in space.

Despina over Neptune [more pix]

I've burned up way too many hours playing with Celestia. My main time-waster has been space "photography". This is accomplished by visiting a location in space, and playing around with time, location, and camera adjustments until a pleasant composition is achieved, then taking a "picture". Celestia currently doesn't support photography on OS X, but a screenshot suffices.

I've published a Celestia photo album on my .Mac site, and intend to do more as I explore Celestia further.