Stellarium

One of my many interests is astronomy, however, I'm not a very good astronomer -- I can only reliably find only one Constellation! While I was at MacWorld this year, I look at all sorts of astronomy programs. Most of them were incredibly complex and complicated, but not at all suitable for a beginner like me. Recently Lifehacker's Download of the Day was Stellarium, an open source desktop planetarium. You can set your location so that you can see exactly what it looks like in the sky. It's easy to use, and best of all, it's absolutely free. I can't wait to use this the next time I stargaze to help me identify what I'm seeing.

Stellarium Astronomy Software