I really like the "teahouse" setting on gmail. It features a fox at a japanese/asian teahouse, engaging in various activities through the day and night.
Harvesting chrysanthemum flowers, eating noodles, doing calligraphy...I can start to see the draw of other virtual friend/pet programs like Animal Crossing, Neopets and even, Civilizations. Basically, something cool is happening and you are in some way connected to that world. Would I like to be living in a Japanese teahouse? sure! (not that I've ever tried, but the concept sounds tranquil and fulfilling) Lonely? This fox has friends that come round at 4pm when I'm checking email. There are even a bunch of ghosts that come round at 3AM if I'm checking email. (that was a little scary though. I haven't checked email at that time since.)
Anyhows, kudos to the designer of this setting ;)