orkut added something new: an application that lets you ask your friends questions. It wasn't developed using OpenSocial, but it's a perfect example of an useful social gadget. You can find it at the top of the feeds page.
Ask Friends (or Mobius, probably a reference to the Möbius strip) has two clever features that make it non-trivial. Based on your question, orkut automatically generates a list of labels, probably from an existing database. Using these labels and other labels entered by you, orkut determines what friends are most likely to have an answer for your question. "The system will choose Orkut friends who may have an interesting answer for you based on their answering history and interests." There's also an option to select the friends that can view and answer your question.
It's a pretty interesting way to target your question and it could be extended to a broader audience, like all orkut users from your country or all orkut users who like Radiohead, not just your friends.
Social networks are containers for web applications. They have details about you and your friends, but this data only becomes meaningful in an application. Your personal data is the input for social applications that aggregate it and derive useful outputs and make your life easier.
"Self expression and communication are often fun and entertaining alone, but OpenSocial is also a platform that can be leveraged to solve real world tasks where the social graph assists us in making decisions. For example, while some might be prone to grab a book at random off the shelf, there are many who appreciate a good recommendation from a friend. With a variety of possibilities in entertainment and interests, it can be useful to facilitate meetings, purchases, recommendations, information management and learning to create a richer, more lasting experience across your application," says Google in an article titled "Social Design Best Practices".
{ via labnol.org }