I've heard the question of whether metal bottle caps are recyclable a lot, and I finally have a definitive answer. Metal bottle caps and lids such as those on beer and jars of pickles are recyclable, but their small size is a problem -- at the materials recovery facility (MRF) they tend to fall through the screens and sorting machines and end up as trash. So there's one thing you have to do to get them recycled: put your metal caps into a steel can and then smoosh the top so the metal caps/lids don't fall out. Then the can and its contents will get recycled. Voila!