I'm for the tattoo too. I have to admitt I don't know a single dog I or any one else around me has taken in thats been scanned. My vet doesn't have one as far as I knwo becaue we asked when we took the last dogs we took in in. If everyone had one at their house I'd see more of a point. I just know that if my dogs got loose and ran off were I live no one would get the dog scanned. they would eitheir take it in,place an add,or take it to the pound. Two of those ways may get them scanned but I'd still trust a tattoo more. All that said I don't think a microchip hurts but people seem to have way to much confidence in them. The only good I see of it is if their is an ownership dispute.