If you’re a registered user on the British Airways website, you’re eligible to get up to $100 off a round-trip flight anywhere in the world through the beginning of September – and if you’re going to London, you can get up to $250 off that ticket. These discounts are only available to people who are both registered members of BA.com and also members of the airline’s “Executive Club” – but if you’re at all tempted by these big discounts, it’s worth checking out.

Once you’ve registered at BA.com, you’ll need to book your tickets by June 30, 2008 and then travel by September 3, 2008. The actual airfare will differ depending on your departure city, destination, and travel dates (for instance, midweek travel dates are going to be cheaper than weekend travel dates), and the amount of the discount you can get will also depend on the route you’re flying. Flights from Denver, Houston, L.A., Phoenix and San Francisco, for example, can get a $200 discount – while flights from Baltimore, Boston, New York, Newark, Philadelphia and Washington D.C. can only get a $100 discount.

The bottom line is that while this could be a great deal, you’ll still want to shop around to make sure the $100+ discount makes the British Airways ticket cheaper than you could get it elsewhere.

Find out more about this BA.com registered user airfare discount on the British Airways website.