Fr Z has an interesting post on the issue of glass chalices (they haven't gone away, you know). Even though they are not permitted in the liturgy, some celebrants and parishes are still attached to these forbidden objects, so faithful priests, when they come into sacristies, will have to have a plan of action ready. So what do you do? Well, when I have been confronted with a glass chalice I just reminded the sacristan that I am very clumsy, and taking the vessel in my hand to admire it, I (accidently, of course) reveal just how clumsy I am. If the vessel survives, it will be replaced with an unbreakable metal one. Problem solved. Same methodology for those awful ceramic things.