6 months ago, I thought all memory cards were created equal. Well, almost. I've been blind-sided so many times since then, I thought that I should share a list of things to know before you buy a Memory Card.

1. Determine the Type. Compact Flash (CF), SD/SDHC and Memory Stick are the major ones.
2. Determine the subtype(s) that your device can use. The Number One problem that people have with memory cards is buying an SDHC (HC=high capacity) card for an couple of year old device that only takes SD; newer SDHC devices can take SD with no problem. Memory Stick has a myriad of different sizes and shapes, each with their own peculiar name.
3. Be sure you didn't buy a counterfeit. Kingston is the most commonly counterfeited brand and has a site where you can verify the card you have: http://www.kingston.com/asia/verifyflash/
4. See if your device has any requirements. For example, SDHC cards have Class 2, Class 4 and Class 6 specifications that define minimum speeds.
5. Some devices have a list of memory cards they have been tested with. If so, stick with one of the tested cards.
6. Some devices just specify brands of memory cards that they recommend. Stick with those brands. You may have to check the Support web site for the device, or even contact Support by phone or e-mail, as the manuals are often too old to be kept up to date with the latest available memory cards and/or test results.
7. Likewise, some memory card manufacturers, Kingston being one example, have a list of devices that they have tested their memory cards with.
   Bottom line: weird things can happen that are related to the memory card. One more word about counterfeit memory cards: they aren't just "knock-offs", but actually fakes, in the sense that a 1GB memory card will be reprogrammed (and, of course, physically labelled) to look like a 32GB card.