<<Disclaimer: Verify this information before applying it to your situation.>>

        I've never tried the particular service Chris mentions, but I've
been using Flifo (http://www.flifo.com) for several years now, and there's
never been a problem with them forgetting to alert an airline that I need
a gluten-free meal.  I entered it in my customer record the first time I
used the service after which it's requested automatically--I don't even
have to think about it, though I am always offered the option of changing
or cancelling it when I book a flight.  I've gotten good fares too
(compared to others going to the same conferences).  I have no financial
interest in Flifo, but recommend them highly--especially if you've been
using human travel agents who forget to ask for GF meals.

        They also let me know quickly--with a warning IN CAPITAL LETTERS
in a email message--when Alaska Airlines said they didn't do special
meals.

Sydney from Seattle