Facebook might have stolen a little bit of CES's thunder last week when it teased the media with a "Come and see what we're building" press invite for a special event this week. Speculation was rampant: was this the long-awaited Facebook phone? No, as it turned out - the new feature unveiled was a novel kind of social search engine the company calls Graph Search.

Whereas traditional web search engines index the huge amounts of web pages on the internet, Graph Search is essentially indexing us. All of the diverse social inter-connections that make up Facebook's body of people-related data (the Graph) can now be searched - in an actually useful and intuitive way - across four key categories: people, photo, places and interests.

In short, Facebook knows a lot about us and it's making it easier for us to access that info more speedily and directly, via search. Examples the company gives of the kinds of searches possible include: "people who like tennis and live nearby", “photos of my friends before 1999” (see above), “cities visited by my family" and "movies liked by people who are film directors".

Facebook's search engine auto-suggests the word combinations based on what it thinks you might be looking for, and by stringing together a few key concepts, you could easily discover (or rediscover) a treasure trove of information and photos which may otherwise have laid obscure in your own social network. While Graph Search is in a limited beta at present, you can sign up here to get on the waiting list.

Also this week - and much more quietly - Facebook implemented a killer feature for US users: free voice calls over data for iPhone owners using the Facebook Messenger app. No official announcements so far on whether this feature will be extended to Australia (or Android, for that sake). We reached out to local Facebook reps and were told: "[T]his is a test and we have nothing to share currently about this feature being rolled out to other countries. For the initial tests, people can only call friends who [are] also living in the US."