Aardvark, the social search service, has just been made available to the public after several months in private beta. The service was open to new users since then but it was invitation only meaning that you had to know someone who was already using it to get in. The limitation is no more and now anyone with a Facebook account can join using Facebook Connect, the social network's login standard.

The newly opened service lets you ask questions and the right answers from your friends or extended social network. The questions can be asked through instant messaging or email and the service will get to work searching your contacts and their contacts depending on their qualification to answer said question. The qualification is determined based on their profiles, which list their expertise and the likes.

Because of the way it works the best results come if you already have friends using the service which is why it initially focused on invitations. And even though the service is now becoming available to anyone you will have to sign up with your Facebook account. This is also intended to help you create a contact list based on the friends you already have on Facebook. Creating a contact list based on your interests is also possible and there are talks about creating topic groups for users with similar expertise.

“I have about 200 friends on Facebook, and they each have about 200 friends. Altogether I have over 10,000 friends and friends-of-friends in my extended network. These 10,000 people have a lot in common with me: many share my school and work affiliations and my cultural reference points. I’m interested in the choices they make and the experiences they have — they are usually more relevant to me than the opinions expressed by anonymous strangers on the web,” reads the Aardvark blog.