Longing for latitude
Interesting feature is that the application has a fine grained way of setting your privacy in relation to the various friends that you have. This I think is a general direction you see in web 2.0 that more and more people are becoming concerned about privacy and about who really are your friends you are willing to share all. In the past I used an application called IYOUIT that was also capable of showing this like this. To me it was surprising how much feeling is involved in knowing precisely where your friends are.