I've figured out how to find many of the things I used to have my friends bring out, but here's some of the things I've brought over in the past:
-apple cider packets (the sugar free ones are good and work with my insulin resistance)
-grits
-mole (Mexican food)
-adobo spice
-Lipton onion soup mix packets (for dips and roasts)
-Hidden Valley Ranch packets
-Cap'n Crunch and Lucky Charms if there's room in the suitcase-my guilty treats that I never actually get
-I had Red Vines on there (or better yet the family mix you can only find in certain parts of the US with red and black combined cuts of licorice from the same company) but I found a tub of red vines at Costco this week!!
-cinnamon gum and breath mints
-Lawry's seasoned salt (for my home baked french fries)
-Mapeleine (I know it isn't as nice as actual maple syrup, but I grew up with easy homemade syrup from it and it's what I'm used to)
-DH has this funny thing about loving the taste of American gummy bears, so someone always has to bring a bag for him.
-non-food, I'm asking dad to bring out one of those suction bulbs when he comes to see the new baby in a couple months.
Oh, I'm in serious mourning about the mother's cookies!! They made several of the ones I've been craving of late.
As for cornbread, I find it super easy to throw together my own from scratch with polenta. I make it often enough here, although I know a lot really miss the little packets of mix.