My 2 cents worth here:
Gracie wears an ID tag with her picture on it. (ok the picture is for looks..lol) No chip/no tattoo..altho I wouldn't be against a chip..I have 4 tats myself..and I sure wouldn't want her to have to endure one if its anything like mine were..I had a choice to sit thru the irritating make ya wanna slap somebody pain...she wouldn't..

AND here is the main reason why I like tags....some people are more likely to stop and check on a stray dog if they are wearing a tag...or that has been my experience. If I see a dog on my street loose and its wearing a tag...I am not quite as afraid to call it to check it out..(maybe that is a psychological thing, I don't know) but for some reason a collar/tag means "more friendly"...that could be way off base, like I said, that is just how my mind works, right or wrong..lol.

She will be spayed in Dec..and I will check into the chip...if its no pain...I can see where you both gain..

Interesting topic ! Thanks for everyone's imput!