This map of how popular different tourist places are was generated by an Estonian programmer using the number of photo uploads to a popular site. Yellow is the most touristy, followed by red, blue is not very touristy, but grey is nowheresville.
I am a little suspicious about the methodology after I saw Toledo, Ohio show up pretty yellow. However, otherwise the map seems plausible. Coasts and mountains show up about as much as you would expect, the BosWash and LosAngeSanEattle regions are hot, and nothing beats European Ye Olde Towne Squares. In the developing world, tourist spots are as expected, including the unjust and sad omission of Africa.
The next image shows a blow up of Africa. The no-go regions are mostly the obvious ones (better book that vacation to Chad before it's spoiled!), as are the Safaris and Coasts in Kenya, Tanzania, and South Africa. Lesser known tourist success stories in Namibia and Ethiopia also show up.
I'm a little more mystified by a blow-up of West Africa. I know vaguely about the tourist success in Gambia and to a lesser extent, along the coast of Ghana. The hot spots in Bissau, Conakry, Freetown, Monrovia, Niamey, Bamako, Abidjan, Ouagadougou, and Abuja are a little more surprising -- perhaps camera trigger-happy aid workers?