Thanks for all the input. Don't think we will go for the annual thing, we tend not to bother staying with one airline for our travel. We have found that the FF schemes are so tight now that there is little value paying more for a flight just to grab some miles. We are looking though at maybe buying at the gate. If anyone has done the LHR-ORD route would like to know how much they usually are on offer for. At the moment they want $95 to pre book. Thanks again.