Do you use any analytics? The Google webmaster interface tells me when external pages are linking to missing pages on my site, or if they have anything indexed that isn't in my sitemap.
Actually that might work. I think there's a tool where you can point Google at your sitemap and it will tell you if their index is different, even if you don't use their analytics.
Actually that might work. I think there's a tool where you can point Google at your sitemap and it will tell you if their index is different, even if you don't use their analytics.