This:<p><i>I installed Loopt on my iPhone when it was launched more than a year ago. I stopped using it soon after, since none of my Facebook friends or Gmail contacts were on it. Now it has more than a million users, so last week I installed it again — along with several other apps — but I didn’t have much luck this time either.</i><p>...illustrates why we need to open up the social graph. It's stupid that every new social feature or business has to build its own registration, friending mechanics, etc., or consent to live in a walled garden of one proprietary social network. Brad Fitzpatrick (of LiveJournal fame, now at Google) has long promoted this idea, e.g. see <a href="http://bradfitz.com/social-graph-problem/" rel="nofollow">http://bradfitz.com/social-graph-problem/</a> . Unfortunately it's still very much an open problem. OpenID is one piece of the puzzle, but the rest is still missing.<p>I'm kinda sorta looking into writing Facebook apps right now, and can vouch that I'd be much less reluctant to dive in if the platform were open.