I store them in a plastic lined cardboard box, lined up so that the conductors don't make contact, and just take them to the hazardous waste disposal center when I have too many... the same place I take used oil and old paint.

Thank god too... the chemicals within disposable batteries are extremely noxious. I think they should also do the same with CRTs (the glass is 40% lead by weight) and backlit LCDs (they use mercury vapor gasses to light the screen). I mean... I think it's law now anyways, but most people just dump them quickly at the county dump...

Though, the only devices I have now that use regular batteries are flashlights and remotes. Everything else I have uses built-in rechargables...