Bark like a dog

If by anti-bark collar you mean an M-67 fragmentation device, then yeah, I think it'll really work.

Maybe give them the advertisement and a stern, but polite letter informing them that their dogs barking is disturbing the neighbors and they need to find an alternative or train the dog.

Is the dog outside and what is he barking at, out of curiousity?

It's out a lot, but not all the time. The main problem is they let it out early (5am?) and fairly late (11pm-midnight), I assume to "go", and it barks like crazy. So it eiter wakes me up or keeps me from sleeping. As far as I can tell, it isn't barking at anything. We think it is retarded and just likes to bark.

The owner obviously doesn't care and I don't think he's going to do squat to quiet it down. He surely isn't going to spend $35 on a bark collar when he could be spending it on beer and smokes. This is why I thought gifting it to him might guilt him into using it.

My prediction is that if you give these people a bark collar they won't use it and you will have wasted $35. But give it a shot if you like.

I would just call the police. It's the same as if your neighbors were having loud parties that were keeping you up. It's a noise violation.

If they aren't scared of the police and they keep letting the dog bark at night, just pretend to be a ninja and kidnap the dog after dark. Take it to animal control and say it's a stray.