Disclaimer (7/7/11): In at least two of my recent posts over the past few days, I made a major goof concerning the nearest stars to the Sun. I labeled them as Alpha and Beta Centauri, when in reality, the stars are known as Alpha Centauri A and B. (Proxima Centauri was labeled correctly). Beta Centauri is another star system altogether, a triple star system about 350 light years away consisting of two blue-white giant stars about 10-11 times the mass of the Sun and 15,000 times as bright, plus a third star that takes about 250 years to orbit the other two. So, extremely different from the Alpha Centauri system. I've gone back and edited the offending posts, so they should be correct. And if you ever notice an error in one of my posts, just drop me a comment and let me know! I'm happy to admit my blunders if they lead to greater enlightenment for others.
A few days after posting my image of the distance between the Sun and its nearest neighbors compared to the average distance between stars in Omega Centauri, The Astronomy Picture of the Day site had a nifty image of the entire triple system, showing the brightness variation between Alpha Centauri A and B and Proxima, which is something I could not do effectively in my picture. You can check out the picture at the APOD website here.
Actually, I suppose I could have hinted at the difference if I'd made Proxima a single faint red pixel compared to A and B.