BA just launched a Facebook promotion called Instant Avios where from now through May 13, 2013, you can play a game to win bonus Avios.
To be eligible, you must follow British Airways on Facebook, and play once a day. If you get three Avios logos, you will get 1,000 Avios. If you get three British Airways logos you’ll get 60,000 Avios. Any other combination doesn't win any Avios.
https://www.facebook.com/britishairways