Exit row seats are available on Delta and Continental at the time you book your reservations if you go through a travel agent. You do not need to be an elite member of their FF program. All travel agents have the ability to get you such a seat, though some may not be aware of it.

You can also get an exit row from these airlines if you go to a ticket office or the airport. They just want to know that you are qualified to sit in the exit row.