Okay, so we’ve all done this before. You change your fluorescent light and wonder what to do with the dead one. Same thing with batteries. The last thing you should do with either is put them in the garbage to go to the landfill. Fluorescent bulbs contain mercury, and we get more than enough of that from the fish we eat (and in some places, the water we drink). Alkaline batteries may seem harmless, but they are filled with a dry chemical mixture designed to produce electrical potential energy (usually 1.5 volts). Just because the bulbs or batteries have been depleted does not mean they are harmless.
Fortunately, there are safe ways to dispose of such toxic tihngs. I recently learned that Ikea accepts both batteries and fluorescent bulbs for recycling. So even if you don’t normally go to Ikea, you can take your used bulbs and dead batteries in. Have a look around. They have some great product. While you’re at it, pledge to switch to rechargeable batteries to power your portable electronic devices. Staples and Home Depot also accept batteries for recycling.
By the way, lead-acid (car) batteries should never ever be put in the landfill. Always contact your local repair shop for proper disposal, or (in Calgary at least) you can take them to your local fire department handling household hazardous waste.
For more information about batteries and battery-disposal, take a look at Calgary Fasteners & Tools Ltd. Granted, this applies mostly to the batteries used in power tools, but they are hazardous and should also not be put in landfill.