What is the bright light in the southern sky?

Question

I live in Illinois and last night I saw what looked like an extremely bright star in the southern sky at about 10:30 pm. It was much brighter than any stars, and I can't figure out what it was. I was wondering if it might be a planet.

Answer 1

http://www.stellarium.org/

This is great freeware that you can download.  Just tell it where you are and it will tell you what you see.  It will answer this and many more questions that you might have now and in the future.  

What you saw, was indeed, the planet Jupiter.  

Answer 2

What you probably saw is Jupiter. It's high in the south right now, by Sagittarius. If you have a telescope, check it out. It's really cool.