I rarely do any heavy structural changes to node edit pages, so until today I hadn't ever had a reason to disable vertical tabs on a specific content type, but there's a first time for everything.
Now there are people who recommend turning it off by editing the $conf variable in the settings.php file... however, this is not an option on this particular site since it is running on Aegir, which automatically rewrites the settings.php file. So I had to find another way. I took a look at the vertical tabs code and came up with an easy solution.