Want to learn a bunch about your webserver? Simply append the domain name on to the end of http://serversiders.com/ and you will divulge quite a bit of background. I’ve typically used NetCraft.com in the past but frankly, I like this better. Cleaner, more detail, etc. and the combination of it and NetCraft provides a whole host of info.
E.g. http://serversiders.com/brainlitter.com yields…