I actually thought of this idea several years ago, but my work with open source has kept it on the back burner. Mark and I talked about it over dinner on Saturday, and it got me . I also talked about it with Tim O'Reilly once, and he enriched the idea, but I figured that if Tim was thinking about this, surely someone (or, more likely, multiple someones) would come along and monetize it. Not yet, and I've been si I actually thought of this idea several years ago, but my work with open source has kept it on the back burner. Mark and I talked about it over dinner on Saturday, and it got me . I also talked about it with Tim O’Reilly once, and he enriched the idea, but I figured that if Tim was thinking about this, surely someone (or, more likely, multiple someones) would come along and monetize it.Not yet, and I’ve been sitting on this for over six years….You know the problem: it’s difficult to trust people online, or even offline. It’s not that people are bad (though, after reading through several British newspapers today, my faith in humanity is a bit shaken), but rather that we have no way of knowing that eBay seller, or that Match.com potential date, etc. is good or bad, or some variant in between (as most of us are). Beyond “bad” and “good,” however, is whether someone is competent, likeable, etc. All of these traits are difficult to measure through current measures (“95 buyers of PopSeller2005 rate them highly”).But they’re fairly simple to measure if you actually know someone that knows PopSeller2005.What if when I went to buy something on Amazon the system could tell me that my friend, Bryce, bought the same thing two weeks ago (assuming Bryce enabled the system to tell me this)? I could then ping Bryce to get his perspective, which would make me more or less willing to buy, but certainly would make me more comfortable in whichever decision I made. Or what if I knew that the eBay merchant is a friend of a friend of a friend? If I trust my friend, I can assume that their friends are probably decent people, too, just as I tend to trust contacts I meet through LinkedIn based on the strength of my bond with the person in my direct network. I extrapolate from that relationship, in other words, to make inferences about the strength of their relationships, and make decisions accordingly.Can you see the potential once a trust network is established?How best to create such a network? Well, through my address book, I would think. If I link my address book to yours, and you link to mine and to your friends’, then we quickly establish a trust network. Of course, I have thousands of people in my address book, some of which I know very little or, in some cases, not at all. (Steve Ballmer is in my address book, but I doubt he’d take my call. 🙂 This is where an insight from Tim O’Reilly comes into play, and which makes this idea powerful. My address book is the starting point, but to make it vibrant and useful the network would also need to suck up data on who I call/email (interact with) on a regular basis. I assume this could be fairly easily done – at least with those that regularly sync their phones/handhelds with their computers – by pulling data from call records, calendars, IM, and email as to my true network. Network all that data together, and I suddenly have the basis upon which to do most anything online, a basis for which I’d happily pay, but which I would no longer need to do, given the ability to charge a percentage of all the transactions enabled by the network:I want to buy something online. The network tells me how well I can trust the seller, or points me to a friend who recently bought the same thing and can advise me on it. I want to sell something online. Perhaps my network tells me who amongst contacts within three degrees of separation is looking for that same thing. I set my network preferences to alert me when my calendar shows travel to a place where a friend from college/whatever lives or is also traveling. The system helps us to connect. I’m trying to hire people for my startup, and prefer to hire people I know or the people they know. I need a babysitter to watch my children. (This was actually the original problem that I was trying to solve with this idea. I was a student at Stanford living in the midst of Atherton/Menlo Park/Atherton, where the kids didn’t need any money and so finding a babysitter was a time consuming and frustrating task.) I look to my network to ask for referrals to good sitters. Filter spam through one’s trust network. I’ve written about this before. Basically, it’s a huge white list that you can send/receive against. And so on….The list goes on, because the basis of entire economies is trust. It’s also the key to open source’s success. Trust removes all sorts of commercial inefficiencies. It starts with your address book. Open Source