British Airways has a pretty decent deal available right now: Book and fly by January 29, and the airline will send you a free companion ticket for use on a future flight. The companion ticket is good for any class of service, so if you book a first-class seat, your companion gets one too.
Here are the details: Once you receive your companion ticket, you must be book between January 4 and July 20, 2010, and travel between January 11 and December 15. All travel must be completed by December 31.
If you’re considering a flight on British Airways in the next few months, this deal may work out well for you, effectively giving you three flights (you plus you and your companion) for the price of two. And all the better if you spring for first-class on the companion leg. Be sure to compare fares nonetheless, to make certain you can’t find a better deal elsewhere, even with the free companion ticket.