Ben Hammersley has just built something brilliant. There's been lots of talk lately about validation. It's hard. Maintaining validation is harder.
To make things easier on yourself, check out Ben's fantastic XHTML Validator to RSS widget. Append a URL to the script, and subscribe to it using your favorite newsreader. Woilla! An RSS feed for validation errors. Updated whenever you'd like of course. You don't even need to think about checking for validation errors manually anymore.
This is instantly useful. Bravo, Ben.