With the prices of flying soaring through the roof, and airlines trying to squeeze every last penny out of you, I have recently found that searching for two one-way flights on separate airlines has been cheaper than booking a round trip flight through one airline. The last two trips i have booked I have done this (one to vegas, one to denver) and getting two one-way tickets has saved me about $80 to $100 each time. It also has the added advantage of giving you more flexibility in the times you are flying, since you are not limited to one airlines flight schedule.