I often thought it would be cool to play certain video games just for the chance for vicarious travel. I love to travel, but never have enough time or money. The idea of doing it virtually partly struck me from a talk I attended (many years ago) by a game designer for a precursor to Everquest and World of Warcraft and the MMORPGs of today. While the game was a typical fantasy hack and slasher, he said he often got letters from retired folks and people in nursing homes who loved the game just to wander the world. One woman wrote how she particularly enjoyed walking to this one bend in a virtual river, just to watch the fish jump out of the water. Something quite reasonable to do in the real world, but difficult given limited mobility, so why not do it in a virtual one.
(Of course virtual worlds today are so sophisticated, one of my colleagues here is trying to use them as a research platform.)
So now I am sort of excited at how google earth is helping recreate the experience of travel, and giving it away for free. The new version of google earth contains a flight simulator, which lets you navigate the real world, modeled through user input and satellite imagery, to explore places you have never been before. Still not perfect, but pretty neat nonetheless.