The digerati have a home and it's twitter. All the people I miss in the bay area are on here. It's like an SMS answering machine ... you don't have to listen to your phone chirp every second when a friend posts some inane thing about the new LOLcats post, you just log in when you've got a few minutes and get all their messages in a stream.
It's brilliant. Do one thing; do it well. Then publish it all with rss so it can infect other sites.
Mobile strategy: designed from the start to be SMS enabled, it's very easy to do the whole darned thing on your phone. J2ME apps are numerous and hit-or-miss ... my flavorites are tinytwitter, twitterberry, and jargong.