Thanks for the replies - it's most interesting. I have never entered a lounge on an economy ticket as I always travel in Club around Europe which comes with the lounge access anyway and hence why I have a Silver card all of a sudden.

It's interesting that one reply suggested opening up an AAdvantage card as well. I thought, obviously incorrectly, that my Silver BA number had to be in the system on the boarding card to gain me lounge access? I assume I just show my card then.....

Also, I cannot find anything about this mileage challenge people seem to be talking about on AA's website. Can anyone tell me where I find out more?