A world map of tourism hot spots. Cleverly made using uploaded photos on Panoramio. One of many excellent graphs, charts and timelines etc on informationisbeautiful.net , including but not restricted too; pop culture time travel timelines, Beatles self reference chart, the Gulf of Mexico Oil spill put in perspective. Be sure to check out the older posts.
Update: check out this for touristyness maps of cities but with different colours for locals and tourists.