Today I had my first look at Galaxy Zoo (it's been up for well over a year and I've known about it from the start, but I'm slow on the uptake sometimes) - an online project that uses the online masses (i.e. us web users) to classify galaxy images in the Sloan Digital Sky survey. Part of the reason behind the project (I think) is that people are actually rather good at image processing in a way that it's quite hard to get an automated computer program to do. So by getting people to do the classification (with multiple people classifying each galaxy for verification purposes) you get a pretty reliable and accurate catalogue - and sometimes get new things spotted. Basically what happens once you sign up is that you get shown a picture of a galaxy and then asked a couple of questions about it's morphology answerable by clicking simple icons, i.e. is it smooth and regular looking, or does it have spiral features, and that's about it - you can then move on to the next image, and the next, and the next... I only did two images on my first go and they were both fairly ordinary looking ellipticals. [ooh, I just got a spiral - there were lots more questions for that!]
One thing I have wondered about Galaxy Zoo before is whether I've inadvertantly got any hits from people who were really looking for it (with this post it'll probably become more likely). Well if you were looking for Galaxy Zoo you now have the correct link to it.