Some do, but it seems pretty rare. I love the idea and wished they would all do something along these lines.

Singapore Airlines had a DND button on the A340 I flew back from SIN. On DL from JNB, one of the flight crew leaders asked if I wanted to be interrupted for anything following the main meal service or wanted to use the call button or flag 'em down method. She wrote the answer on a sheet of paper and it worked very well; I wasn't interrupted at all. On a different TATL, I was constantly asked if I wanted something (to the point of being very annoying).