A change in the demographics of your life due to IM
When I left high school, I didn't look back. I have a few friends from HS, but mostly I found many more like minded people in university. That seems to be a male trait, in that more women seem to keep a circle of friends from HS than men do, but for those that find themselves at university, this is where the social circle that may stay with us our entire lives is formed.
However, today, university frosh, both male and female, and keeping in constant touch with their HS friends via instant messaging and VoIP. They don't remove you from their buddy list because you went to different schools. This means they are keeping more and closer friends from their HS days and also are more in touch with life at other universities.
I expect this will have far reaching consequences, not all predictable today. To how people live their lives, how they socialize and go on vacations, and how aware they are of the world outside their new university life. With buddy list presence, these remote friends are gaining an intimacy in some ways higher that we used to give to local friends.