I've always been fascinated with how some of the big sites are built. Does anyone know of a good site that lists the architecture of the Top 500 sites for example? I'm interested in what they are built on for example J2EE, Perl/Python, MySQL, Oracle, .Net, etc.. I would like to learn how some of the more heavy traffic sites are designing and building their site architecture (i.e. MySpace, Digg, LinkedIn, SlashDot, etc.).

It's a good question, but I don't think you'll find that answer for security reasons. if the top 500 sites revealed as much as the programming language they were built with, there would be hackers and other idiots trying to get in through the back door.