International Travel

I am going on a trip! I am very excited, but a bit nervous about long flights and snacks. I have called the airline, twice, requesting a gluten-free meal. (The first call, lasting a half hour ensuring that I was "all set" apparently didn't work because the second time I called they had no record of a dietary request. This has lead me to believe that calling a third time to check, perhaps the day before the flight, is also a good idea.)

Do you have any stellar travel snacks?

Any recommendations about what will and won't survive the security check?
(fresh fruit, open containers are out... but I am thinking that a package of almonds should be ok)

Thanks!