I'm not sure where to put this question, so I try it here.
Thanks to this site I learned how to setup a backup MX record for a mailserver. The second server just holds the mail untill the first server is back online.
Does something like that exists for a webserver? What I mean is, when a webserver goes down, can I forward to another server showing a 'sorry' page? Maybe with a dns record? The second webserver doesn't have to have a backup of the site, just one page for all requests.