Trip Insurance on a free ticket?

Q. I have very carefully accrued frequent flier credits in order to earn a free flight and I also recently received two free round-trip vouchers for giving up my seat on an overbooked flight. I'm excited about these opportunities for free travel, but, since I'll be putting time and money into planning all the other details of these trips, I'd like to insure these tickets as I would a regular ticket, including in the event that the airline folds. I know that I shouldn't buy a policy from the airline but straight from the insurance carrier, but is it even possible to buy insurance for a flight I technically didn't pay for? Can I pay for a policy that would cover the amount of the ticket price at the time I booked? That way, even if the airline folds, I can get a ticket on another airline without paying a lot more for a last-minute fare.

A. As far as we know, insurance companies will not insure your voucher tickets or frequent flyer awards tickets (pre-9/11 there were some policies that could be purchased to cover these kinds of trips)... however, trip interruption insurance is still available for that type of travel.