I always wear my celtic knot pentacle (its a pewter pentacle with a ring of celtic knotwork surrounding it) and my other slightly larger celtic knotwork pewter pendant.
(Can you tell I love pewter? :P And that I'm Irish? XD )

I feel naked without them and very uncomfortable without them to the point that I don't feel right leaving my house without at least one of them on. I've been wearing them both for years and they're practically part of me at this stage.