Tobias Leingruber, a German artist, has created the first Facebook ID cards. While obviously being a novelty, the cards feature a realistic format featuring the owners profile photo, full name, username (url extension), profile ID, gender, country of residence and join date. The exquisitely themed cards also include a QR code, so smart phone users can quickly find and add your profile.
Tobias was offering to print these cards until Facebook shut down his site - FB Bureau. Perhaps Facebook is planning something of it's own? A new method to login to your account on your mobile phone using the QR code?
Mortiz Tolxdorff was inspired by Tobias' idea and created a similar card for Google+ profiles. Instead of offering a printing service, Tolxdorff has produced a modifiable graphic - at the time of writing, his site seem to be down too. Update: His site looks to be up and running!