Well, to show you how far behind the times I actually am, I finally got my “orkut”:http://www.orkut.com/ invite. I’ve never been that interested in this whole ‘social networking’ thing, but after a few minutes of playing around with it I realised that all Orkut is doing is providing a framework for communities that already exist. Many of us are members of mailing lists, forums, have people we know socially or just via the web. Theoretically a system like Orkut (and its by no means the only social networking system out there) can replace many of these.
I did have a few other thoughts about Orkut (and the other social networks out there):

* The market research information gathered is fantastically valuable. The value of market research information increases with its verbosity – the more specific the information gathered, the more people want it. Orkut encourages you to to answer as many questions as possible as it helps you describe your persona via the system – whether or not to show you more accurately to people you already know, or in order to meet new people. If Orkut remains a free service, don’t expect it to be too long before you start seeing highly targeted adverts.
* Something like this could form the basis for an anti-spam solution. My filter could quite easily say “I don’t accept mail from someone I don’t know via Orkut”.
* In line with the above, stick a decent web services API on it and integrate it with your PIM software – suddenly your friends become your email contacts, community events get loaded onto your calendar…
* In line with social bookmark managers like “del.ici.ous”:http://del.icio.us/ or social RSS aggregators like “Bloglines”:http://www.bloglines.com/, I could store my feeds and bookmarks in Orkut – these then become resources for my friends.
* Use it to agregate my existing blog, thereby displaying what I’m currently up to on my Orkut page.