DoublecheckDoublecheck pulls a sitemap file and checks each URL listed, outputing a list of URL's for each HTTP status code that is encountered.
$ gem install doublecheck
$ doublecheck http://example.com/sitemap.xml
NotesGet the code: github.com/nathanhumbert/doublecheck
Doublecheck is pretty simple at this point, it does one request at a time, so large sites may take a substantial amount of time to process.
Google's webmaster tools will eventually let you know if one of your pages has a problem, but it isn't a particularly fast way to find issues on your site.