I've heard most of the urban legends mentioned here. Let me add a few others, and some comments.
I remember the one from the Yearbook on Germany. Gestapo walk into a room, and somehow miss seeing a brother who is seated there. Brother finishes whatever mission for Jehovah he is on. I was always disturbed by the fact that the brother was captured and executed by the Nazis shortly after this.
Demonized Smurf dolls and old furniture - must be a thousand of those stories.
One that I heard different versions of many times was about a brother going h to h with a new brother. Householder threatens to let his vicious dog loose on them. New brother steps in and says, we'll leave, but hold on to your dog. HH lets dog go, and brother kills it with a single blow. Turns out, of course, that he had been a dog trainer in the military.
One I heard from Europe was the man who is reading a Truth book on a train. A man in his compartment becomes enraged, and throws the book out the window. In various versions, either the book hits a man in the head who is about to commit suicide, or the book goes into the water, and a man about to commit suicide by drowning finds the book as he's wading into a lake. Voila! Reads it, and it saves his life. He tells the experience at a convention, the brother on the train is there and hears it, brother saved from suicide and other brother meet, shows the Truth book, all bloated and water stained, etc etc.
Sister going door to door, and rapist, (or whoever), sees two big men with her, is also a common one. That and the rapist/thief under the bed hearing the prayer is also widespread.
Being swallowed by the snake - that's a bit farfetched even for the Witnesses. If you're so far out of touch with reality you can't tell if you're being swallowed by a snake - you deserve to be.
When the Australian KH was bombed, the story was that the moment the bomb went off, everyone was looking up a verse, which minimized injuries, as they were all looking down. THAT must have been a HELL of a consolation for the families that had members killed!!
I interviewed plenty of friends at dc or ca who said they received, sometimes to the penny, a check or a gift that they vitally needed at the moment (new tires was a common reason). Some of these folks I had no reason to doubt. Then I heard the same stories regardingd Catholic nuns, Mother Theresa, protestant missionaries, etc.
S4