This is the tag we use. I have engraved on it (they cost me $10.20 including the shipping. No hanging tag, can be moved from collar to collar) - boomerangtag.com
Samantha
My name
cell #
Husband Name
cell #
My opinion is that my dogs' tags are in case they get lost, the finder can actually find ME. I have their names, our address and my cell-phone number. In some ways, that could be bad, but I want to make it easy for someone to give me my dog back! What I want to do is order tags with their dog license numbers because those tags just aren't lasting 3 years.
I have mine and my husbands names, our phone number and address, I live in a rural area/small town though, and I probably wouldn't put much more than my: First Initial, Last name & cell phone number if I lived in the suburbs or in a big city.