two things...
1) gotta love the ad by google at the foot of this thread for TCP/UP
2) Have an itin booked where we're flying out with my parents but they're on a different flight/route/date home. Having got somewhat irritated by BA messing around with the seat allocations, I explained in farly pointed terms what was going on. Later they made an arbitrary move of seats, but moved my folks at the same time.