Soy Sauce
All soy sauce has wheat. You can get
Tamari, which is a good substitute at most Cubs and Rainbows as well as Co-Ops. But this makes almost all take-out asain food suspect. The one exception being Thai food, that usually is not cooked with soy sauce and uses rice noodles.
Diet or Low Fat Food
Many diet products, that seem like they would never have wheat, remove the fat and add wheat in as a thickener. Some examples of this is low-fat sour cream often has wheat.
Broth
Wheat is often used as a thickener - Progresso is our go to brand. It says GF right on the label.
Chapstick and lip products
Wheat is often used as a thickener - alas - you will have to read the label.