Looking beyond the merits of this particular use, this is a great idea for creating valuable backlinks to your site. I wonder what Google thinks of backlinks on

Looking beyond the merits of this particular use, this is a great idea for creating valuable backlinks to your site. I wonder what Google thinks of backlinks on 404 pages? I suspect it treats them the same as links from other pages. 404s appear when there is a bad link, and Googlebot follows all links, good and bad, so there is quite a potential here for increasing your backlinks if you can get your code on somebody's site. Wordpress plugin, perhaps? :-)