A) There are several advantages to downloading photos with a card reader:
• Depending on the camera, the card reader will be faster. Your camera might use the older USB 1.0 standard or, if it uses the USB 2.0 standard, it might not use the Hi-Speed version. If that's the case and your card reader supports Hi-Speed USB or FireWire (IEEE 1394) and your computer supports it as well, the reader will win out over the camera.
• You must power the camera while downloading to your computer, so you need to have a fully powered battery. If you can use an AC adapter, you still have the challenge of knowing where the adapter is and then plugging it in and out of your power strip.
• If you download from your camera, you may first have to make sure you have the proper drivers for your particular operating system. Most readers work with the most recent Mac and Windows OS without installing additional drivers.
• Often, there's no good place to set the camera when it's connected to your computer. Earlier this year, I received an e-mail from a reader whose camera was knocked over while downloading. Three things happened: 1) the case on the camera cracked; 2) the USB port on the computer shorted out; and 3) when the USB port shorted out, it damaged the media card in the camera.
One note on using a reader: Don't format the card using the reader; only format the card in the camera.