The importance of formatting your memory card

Formatting your memory card (xD, SD, Compact Flash, etc) is very important.
Unlike erasing, formatting improves the overall performance of a card.

Think of it like the hard drive on your computer. There are always hidden files and folders, and just deleting the files that you can see does not remove the hidden objects, which then creates sluggish performance, etc.

It’s best to erase and format memory cards in the camera, not on your computer. If you plan to use a memory card that was used in another camera, format the card in the new camera before using it to store photos.

Get in the habit and add it to your list of things you do each time you download your files. What? You rarely do that and keep 500+ JPG's on your memory card? That's not good, especially with the accidental chance of erasing them by mistake, magnetic forces or battery drain could cause a malfuntion and format the card.

So each time you come back from a trip, shoot or walk around town, try to do the following:

1. Download the files off your camera (via a card reader, not a cable) onto your hard drive. Make sure this is an external drive or slave drive, not the drive that you operating system uses. Once downloaded, and your metadata to the raw files and then back them up somewhere else. Either locally, a DVD, online source (shutterfly, flickr, etc), or sign up for Carbonite (highly recommended).
Remember, all of that data transfers over to flickr and other stuff as "tags".

2. Format the card in the camera.

3. Clean your lens and the lock the mirror up for cleaning. Do not use tissues or cloths, use photo wipes or specialized cloths.

4. Charge your battery!

Now you can relax and know that your camera is ready to go for the next shoot and your photos are safe.