Good question. I'd like to know what the official policies are, since I'm rather tall, and the exit rows are definitely a plus in terms of leg room. CO has consistently told me that exit row seats cannot be assigned over the phone, since they have to (visually) verify you qualify to sit there. However, I was told by a res. agent on the phone that if you checkin at the airport and ask to have exit-row seating as a preference added to your fflier account, you could, and thus res. agents on the phone could access this in the future and assign seats in advance. What do most airlines do - hold exit seats for elites that don't get upgrades? I'm curious too about the exact policies on this.