While it isn’t much help to the average traveler, it still is fasincating to check out the way the sun moves across the planet and see who is in the darkness of night and the bright light of day. The Opentopia – World Sunlight Map provides a live view of the sun passing over the planet at any time of the day.
If you are calling a friend who lives on the other side of the planet, this is a good way to check if they might be asleep or not.