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

Burger King has added a list of allergens to their website:
http://www.burgerking.com/Food/Nutrition/NutritionInfo/index.aspx

From that list I determined that the following were WHEAT-free, but not
necessarily gluten - free:

LUNCH & DINNER
  - Side Garden Salad (w/o Dressing)
TREATS
  - Shakes:  Vanilla, Chocolate, and Strawberry
  - Iced Coke
  - Iced Cherry
CONDIMENTS
  - Jam:  Strawberry, Grape
  - Sauce:  Honey Dipping, Ranch Dipping, Zesty Onion Ring
  - Salad Dressing:  Kraft Light Italian
  - Cheese:  Cheddar, Parmesan

French fries are cooked in dedicated fryers.  However a common fryer is
used to cook the following items:  Breaded Chicken Patty, Chicken
Tenders, BK Fish Filet, Onion Rings, Breakfast Sausage, French Toast
Sticks, and Hash Brown Rounds.  An individual with a known allergy that
desires to consume an item cooked in our common fryer needs to review
all those items

Obviously they don't address what meats would be wheat free if served
without a bun!  Anyhow, I sent BK the above list and asked them which of
those items could also be considered GF.  I got this reply (via
snail-mail):

"At this time Burger King Corporation does not have a list of gluten
free products.  Thank you for bringing this matter to our attention.  A
copy of your comments have been forwarded to the appropriate management
team so that they too may be aware of your concerns.
Sincerely
C. A. Planas - Consumer Relations Supervisor"

Website:  www.burgerking.com/

Link to sandwich contents:
www.burgerking.com/Food/Nutrition/sandwich_content.aspx

Link to ingredients in their food:
www.burgerking.com/Food/Nutrition/ingredients.aspx

* Please carefully compose your subject lines in all posts *