You’re busy, so let’s just jump in with some memory card facts you might not be as familiar with. We’ll get right into their speed ratings, their wireless capabilities, and . . .

Their what, you ask? Their wireless capabilities? See, we told you there might be a few surprises ahead. Let’s get right to them and follow up with some card basics afterward.

Performance

The first thing to know when buying memory cards is that not all are created equal. To be sure, they do all meet the basic criteria for removable flash memory storage media, which is to store data such as photo and video files from your digital camera. That said, there’s quite a difference in the performance of entry-level cards sold at commodity prices and high-end cards targeted toward professional photographers.

If you’re shopping for a flash memory card for a digital camera, the key thing to look for is its Class number, such as Class 6. This tells you how fast the card can save photos, video clips, and other files in megabytes per second. For instance, a Class 6 card can store data at 6MBps, which is pretty fast.

A fast memory card can speed up your camera’s ability to take second, third, and other photos after the first. That’s an improvement you’ll seriously appreciate when you’re taking photos of a friend who is finishing her first marathon and jogging swiftly by. Many users find that their slowpoke digital cameras feel much livelier when they pop in a faster card. Of course, for less demanding devices such as digital photo frames, a cheaper, slower card will perform just as well.

Wi-Fi

Another lesser-known trait of memory cards is the fact that an elite few of them such as those from Eye-Fi ($39.99 and up; www.eye.fi) can not only hold your files but can also (after a bit of setup) automatically upload your pictures to a computer and/or a Web site over a specific wireless network. For instance, a wedding photographer can snap image after image, safe in the knowledge that his RAW image files are being wirelessly replicated on his nearby laptop. A young socialite, on the other hand, can update her Facebook, Flickr, or other online service account as she takes pictures of guests at her birthday party.

Basic Details

Other items you should know about memory cards are a little less, um, flashy. They come in different types, such as SDHC (Secure Digital High Capacity), as well as in variants with different physical sizes, such as microSD. But before you buy any memory card, check the users manual of your mobile device for compatibility, even if the card should fit.

Finally, memory cards are marketed according to their capacity in gigabytes, such as 4GB, 8GB, or 16GB. The more a card can hold, the more photos you can snap, so buy accordingly.

by Marty Sems