Over the summer I visited my sister who is allergic to everything. I mean, everything--soy, nuts, seeds, casein, and I can't remember what else. So when it came time for us to grill some bison steaks (she can eat meat!) I had to find a way to distinguish her steak: the one without the allergen-filled sauce.
I wish I'd had some Grill Charms on hand. These are little stainless steel charms you place directly on your steak (or hamburger, portobello mushroom, ribs...) to distinguish whose food is whose. It's a great idea for any group of people with different tastes, but especially helpful if you're trying to keep track of food allergies!
Incidentally, the founder, Leslie Haywood, is a breast cancer survivor. So my favorite Grill Charms set is the Pink Collection --10% of profits go towards finding a cure for breast cancer.