Thanks for the tips, everyone. While I'm unsure about using the correction collars (my husband is especially against it), at least now I know of a few reliable brands by posting here.

I will try the quiet dominance technique for now, since I do believe that barking is okay at certain times (like playing). If he does not show any improvement in the next week or two, I will have to move onto other options.

Chris, I agree wholeheartedly with what you are saying. Rest assured that was the first thing I did. It does make things easier that my dog is so cute and small, which disarms the neighbors!