I followed the uninstall directions for "Removal when using rEFItBlesser", because when I installed it, I ran "rEFIt.mpkg" (i.e. the installer package). I trashed the "efi" folder, and "rEFItBlesser". I restarted the computer twice, and the menu still appears when the computer starts up.
It seems that the solution is the same one listed there under "troubleshooting". Initially I was thrown off by the wording used. I thought that "If Mac OS X no longer starts up.." meant OS X didn't start up at all, but what it really means is "If Mac OS X does not start up automatically instead of rEFIt..."
I just followed the directions listed there and now it uses the default boot sequence.