Actually, a cheap flight will be okay for mileage redit from Mexicana, United, Air Canada, Lufthansa and I think a few more. It is British Midland who are insisting on top airfares to qualify for 55,555 miles from them.
Kempis - Yes, there is a brand new Hilton about 5GBP taxi ride from airport (they may even have a shuttle). Be sure to fly into Belfast Harbour Airport and not belfast nternational. The taxi ride to International is around 25GBP. My wife and I spent last last Saturday there and was very nice. We were surprised at just how clean downtown is and the ease of getting from the Airport to the City on the shuttle bus (2 GBP).
There is an American style AMC24 cinema complex there as well as some beautiful old buildings and an interesting dockyard area. At no time did we feel unsafe.
Dave - London,UK