SDIO (Secure Digital Input/Output) cards fit into SD card slots, but they are very different from SD cards. SDIO cards are usually slightly longer than SD cards. That means they protrude from the gadget to which they’re connected. Additionally, many of them have attachments at the end.

SDIO cards are really quite remarkable. They can add Wi-Fi and Bluetooth to gadgets. They can also add GPS, a TV tuner, fingerprint recognition and more.

But there's a catch. Not all SD drives can accept SDIO cards. For example, many handhelds and smartphones are SDIO compatible. But I know of no digital cameras that will accept them.

That’s unfortunate. I know many people would like to network their cameras with their computers. But to do so, your camera must have wireless capability built-in. Canon, Nikon and Kodak all make such cameras.

If you want to use SDIO cards with your handheld or smartphone, it must be SDIO capable. Consult the manual or check on the manufacturer’s site.

Next, make sure the SDIO card itself is compatible with your particular phone or handheld. This is very important.