Forget the burger wars. It seems the new battleground in the world of fast food is the breakfast sandwich. Consider that Sonic SONC, +1.15%  , with 3,500-plus restaurants spread across more than 40 states, has just started rolling out its French Toaster, a sandwich that features the usual morning fare - eggs, cheese and sausage or bacon - but with a twist: Instead of plain ol' white bread, the wrapping is (you guessed it) French toast.