My cat wears a collar, and so did all the cats I grew up with. If you get them used to it when they're kittens, it's not a problem.

As for microchips, they're pretty painless, which I know is hard to believe when you look at the width of the needle. Lets just say that I've implanted them many times and the animals never even really flinch. Once it's in, it doesn't bother them at all.

And if you compare that teensy bit of pain to the good that they do... Just think, your pet might get put down at a shelter if they don't know whose it is, but if it has a microchip they can contact you the owner and get your pet back home safely.