Barking Dogs  

My dogs have a common, and yet very annoying problem. They bark all the time--from passing neighbors, to the mailman, to what sometimes seems to be nothing at all. There is a lot of advice out there, and I would love to discuss these choices and get some feedback.
The first method involves squirting water at the dog each time he or she barks. This is supposed to get the dog's attention off whatever he or she is barking at and focus on you instead. What is great about this method is it works instantly; however, the real question revolves around the long-term benefit. Does the dog really understand why you are squirting water? Is it scaring the dog and harming your relationship?The second method, so I have heard, is the shock collar. It works much like the water bottle method, but it administers a shock instead of a squirt. The same pros and cons apply; I believe this method is a bit inhumane, but the shock sure does get the dog's attention.
The third method is treating the dog to give him or her a positive association with passing strangers. Before the dog sees the stranger, give him or her a bit of a treat. Continue this as the stranger passes. If he or she starts barking, give the dog the "watch me" command to distract him or her until he or she is quiet; then, start the whole process over. Over time, this will help alleviate any anxiety associated with strangers.
The method you chose depends on whether you prefer positive-based training or punishment-based treatment. There is a lot of debate in the training world about which is more effective. Currently, I believe more are leaning toward positive training due to the fact, according to many trainers, that it helps you maintain a positive relationship with your dog.
I would love to get some feedback on this. What do you think?