Kayak answers the age old question, when are holiday airfares cheapest?

Travel search site Kayak.com processed a whopping 443 million searches in the first half of 2011. There is an information gold mine buried in those hotel and flight queries, as well as answers to some of our most pressing travel questions: Is it too late to get an affordable plane ticket for the holidays? Are you paying more than average for airfare? What days of the week are cheapest to fly?