The hard coded URLs in the database and settings.php for the forum and themes makes it not possible to setup an alternate address to view the site by. When I switched hosting providers some of my members couldn't view the forum for a week due to their work incorrectly caching the domain. The majority of them were able to view it within hours. Had SMF grabbed the url with PHP's $_SERVER functionality I could have given them an alternative address to use. Giving them the static IP wasn't an option since I host multiple sites off my server.
What is repair_settings.php? (http://www.simplemachines.org/community/index.php?topic=18096.0)
I know what repair_settings.php is and I also know how to make the changes by hand. The issue was a handful of my users couldn't get to the site, but the majority could. It would be confusing to tell everyone to use an alternative address until those few users could get on. Instead I told them to just wait it out.