I noticed today that the Google Webmaster Tools offers a widget you can place the code on your 404 pages to help customers for those pages which no longer exist.

This is what the widget does on the 404 page:

It adds a search box for your site with appropriate search suggestions.
It tries to provide alternatives to incorrect URLs.

Where do I edit this page?

Pages > Predefined Pages > Page Not Found.

Were you able to get that script to work. When I tried to enter it into the Code for the Page Not Found page, I got Script Errors and even though I eventually got the script in it did not do anything. Nothing even showed up on the page.

No I was not able to get the script to show up either but after looking through things I do not think this is something we need since the pages not found we have set to still go to our website just not the page the person was looking for. The page that comes up is the "Page not found", which is still a page on our site so they can click through our page and look for what they need.

I think the widget is for those sites which just show the normal browser page can not be display and does not direct to the site. Then we would want to use this widget to provide the URL of our site so the customer can click it and still get directed to our page and we are not loosing clicks.

I just made a change to our "Page not Found" and added some information to it so that customers know what to do and why they ended up on that page.