This a quick post about validating the code on your web site because I happened to be thinking about it today. Usually, validation is one of the first things I check when something breaks on a site. Running your site through a validator is a good way to spot errors in your code quickly.
Although I support standards and build sites based on them, I am pretty lazy about vaildation. I have the HTML Validator plugin installed in Firefox. Usually, all I do is check for the green checkmark there, and I am good to go. I recommend doing more than that though and making sure you run your entire site through a validator at least once before you launch. However, having the HTML Validator installed will help you check your code for errors on the fly, and save you time in the long run.