I ran into an ad for Railroad Tycoon 3 just now and started thinking how nice it would be to have railroad servers for me to visit and to build within. What is a railroad server? It's basically a persistent, modifiable 3D model server specialized in trains, tracks, passengers, buildings, and landscapes. Well, maybe some cowboys and indians.
One would need a client to view it, but a browser plug-in should make it easy enough to use. One thing nice about it is that there is no pressure to chat. Just the quiet immersive view for relaxing and occasional trains that goes by or to ride on. If another person is nearby one can chat, but it's optional. Some people would choose to build trains, train stations or buildings. Others would play with the landscape. Railroad servers could be connected to each other so one could 'ride' from one server to another, crossing continents and time periods.
Railroad servers might seem boring when compared to MMORPG games like EverQuest but I think they are more appealing to the mature crowd and train enthusiasts. Is there a business model? Nope. But I wouldn't mind paying a few dollars a month to have a little patch of land on a railroad server for me laydown my own tracks and to run my trains.
I guess one could even stretch the idea into the realm of social networking software. The problem with traditional social networking services like Friendster or LinkedIn is that there is no place go. It's like dating on a piece of paper or holding a meeting in the dark. A Place serves as an excellent context/medium for social connections. Lacking cohesive context, a social network is no different from a bag of marbles. Open the bag and marbles will roll out.