Blimey! Google might not know about it (not that I could find, anyway), but Microsoft have an inspector add-on for IE7. I’m using it now in an attempt to work out why the &%&£ IE is barfing on some sub-pages but not others, and why it’s ignoring .asset-heading a:visited when Safari and Firefox are both doing what they’re told.
[update: of course, the inspector is telling me that a specific element is set to display as white, with no text decoration. When it’s actually showing as grey and underlined. Huh]