Going one step further, it would be very nice to be able to supply information to different users based on their group. This is another thing which is lacking i

Going one step further, it would be very nice to be able to supply information to different users based on their group. This is another thing which is lacking in Facebook. In fact it is something which is currently lacking from every social network (that I'm aware of at least). Everyone scrambling to build the next Facebook in the wake of the recent debacle may want to take some of these ideas. For example, in your "About Me" section, with your co-workers you may want to say that you enjoy programming and playing around with server configuration whereas with your old college pals, you may want to say that you miss the days of binge drinking and getting laid. You would not want either group to see the other explanation of who "you" are. Specifically related to this idea, you may want to have enable your college pals to see that you are attending "Remembering the good ole days kegger reunion party" while you may want your co-workers to see that you are attending a conference on some technology. You probably do not want them both to see the events that the other sees. On a basic level, I like how Google Voice handles this. You can specify a certain voicemail message to be heard by people who are not in your phone book, and different voicemail messages for any groups you have created. This allows me to have a silly message played only for my friends and not worry that an important call will come in from an unknown number and get my silly message. This concept expanded to any and all properties of a social network seems crucial as far as I am concerned.