I can't speak for the rest of the country but I can assure you that in Florida, there is no such thing as a "No knock" warrant. Having written and executed well over a hundred warrants (mostly drug related) I can safely say that no judge in our judicial district (or any I've heard of) would sign off on a warrant if you put a no knock stipulation in it.
Can you get away with a short knock and announce? Sure. It all depends on the circumstances, the type of warrant, the suspects, the type of violation etc. If you are executing a warrant on a residence occupied by a group of armed gang members wanted for robbery, you can probably justify, from an officer safety standpoint, a short K&A. The courts recognize that serving a warrant is dangerous and unless there is obvious, intentional midconduct on the part of the officers, they will grant some leeway.
If you're hitting an indoor marijuana grow where the suspects are not known to be armed or violent, you'd better give a longer K&A. Why? Not as much obvious danger and it's nearly impossible to destory the evidence of a grow in 60 seconds. Now, if they see you coming and run back into the house...it's game on with no K&A required (they already know that you're there and they're apparently not going to cooperate and let you in)
The key (in Florida anyway) to the whole K&A thing is to allow a "reasonable" time for the occupants to answer the door. Now, define reasonable? It depends on many variables and is not set in stone. If we knock and no one answers but we can hear people scrambling around inside...we're coming in. We don't know if you're destroying evidence or getting a weapon.
As for hitting the wrong house, I have never personally seen how it can be done if you (as the officer writing/executing the warrant) do your job properly. We've all heard the horror stories so it does happen but thankfully, it's the exception. As mentioned by another poster, if you are on the receiving end of one of these exceptions, the best course of action is to cooperate immediately. Any attempts to do otherwise will be delt with. Remember that we don't know at that time that we're in the wrong house and will just assume that you're a BG with a gun and take the necessary action. It's not the time to try and engage in gunplay or dialog. Let the team secure the house and let the smoke clear...believe me, the mistake will make itself evident pretty quickly
Believe me in that there will be no doubt in your mind that it's the cops. My suggestion is live to sue as you'll have a great law suit if they hit the wrong house.
For those who have never written or executed a search warrant, I would suggest reading some to see the amount of work that goes into them. It's not rocket science but you have to have your ducks in a row