I have checked out Open Social, a common set of APIs which can be used to build social applications that work across multiple websites. I think it is really cool and at the same time not so good.
I think it is cool because, there will be a lot of applications that will be created for Orkut now, just like those you find on Facebook. But at the same time, the saddest part is that there will be many useless applications which will clutter the site and confuse everybody.
Google has announced that Open Social applications will be available to users now. So, gear up and be ready to see it on your Orkut login sometime soon. Earlier, these were available only in the sandbox.
Well, I am looking forward for an application which could allow you to tag and share photos from your friends' albums. I really like few photos from my friend's photo album and would like to tag them so that I can easily see them when I want and also would like to allow our common friends to see what I have tagged. Hoping to see if something similar would be available.