I don’t usually talk about frequent flyer issues here, but this warrants a mention: As of late last week, you can now redeem American AAdvantage miles on British Airways (and vice versa) (Gary has all the details here). Because of anti-trust issues, you previously could not earn or burn AA miles on British Airways’ Europe flights and you could not earn or burn BA miles when flying American to Europe.
That’s all changed, but there’s a catch: British Airways charges ridiculous fuel surcharges to their reward tickets, so whether you are using BA or AA miles, you may find $500 (or more!) charges on top of the miles. Bleh. You may be better off connecting on AA, Iberia or Malev (!?) when flying to Europe.