When he nips at you, give a yelp/ow/something to that effect and immediately turn your back to the pup or even get up and leave the room. Essentially when nipping/biting happens, ALL play stops. ALL attention stops. Do NOT push him away (that's just a sign of more attention and play to him )
The key to this is to be consistent - everyone involved with the puppy has to be on board and willing to do this in order for it to work.
And yes, please don't use the tap on the nose.. the puppy may think it's playing still (and therefore, wouldn't work) and secondly, as your puppy gets older - they may very well take exception to it.
+1 LL! saves me from typing