Until 12/31/05 you can earn America West miles flying on British Airways and then convert them into USAirways miles when the two FF programs merge. The biggest catch is that BA only gives 25% of actual miles (and no credit for status qualification) for discounted coach tickets. At least with America West you'll earn miles on the transatlantic portion of the trip. If you were trying to earn AA miles on BA you wouldn't earn any on the leg across the Atlantic Ocean.