> I just installed it and tried a few bad URLs that were close to being
> correct, and it worked very well.  As noted in the Webmaster Tools,
> the widget did not produce a link to my HTML sitemap, perhaps because
> the filename is "sitemap.htm" instead of "sitemap.html".  I hope that
> the widget gets a bit smarter about sitemap filename extensions soon
> (.htm, .php, .asp, etc.).

> The Webmaster Tools page for installing this widget should also
> include some advice to add a complimentary <noscript> section to your
> Custom 404 page so that you can give users running with JavaScript
> disabled some appropriate advice for finding their way to the
> information they're after on your site.