YSlow - a Grade A Tool
I spent a couple of hours running the YSlow FireFox extension against the main website for one of my little side projects and I couldn’t stop fiddling with the sites config until I got the score up. Improving a category until you get an ‘A’ gives you that same moment of satisfaction as all your tests passing or a file restore working perfectly.
Due to not being amazingly wealthy I cheated with the content delivery network stage and just overrode it with the sites own name.
I’d happily recommend this tool to anyone who wants to learn some good habits. With the exception of the CDN rule it’s hard to argue with most of its suggestions. The performance grade is a nice way of giving near instant feedback and encouraging at least basic sensible behaviour.