OUTDATED: Since the release of Cataclysm, this addon (which was hardly complete anyway) is thoroughly outdated. I don’t intend to update it, but feel free to fork if it takes your fancy.
TourGuide – Explorer
An addon for World Of Warcraft
TourGuide – Explorer is a small addon to help players working towards the World Explorer achievement.
Thanks to commenters on Wowhead.com, particularly Skeeve.