This is a simple guide to buying Flash Memory Cards for your device, be it a Digital Camera, Mobile Phone, PDA etc. These cards are designed to give additional storage space or memory to that already included in your device. For instance, if your Digital Camera has internal storage capacity of 16mb, then the insertion  of a Flash Memory Card into the card slot will add storage space  up to the capacity of the card. So if your device uses Secure Digital (SD) cards, then a 256mb card will add 256mb of storage space, giving you a total of 272mb.

The Flash memory technolgy used in these cards allows for the storage of data on a non-volatile basis, i.e. when the card is removed from your device, all the data stored on the card stays and is retained. All power used to run the card, is supplied by the device being used, e.g. the Digital Camera. MP3 player, PDA, mobile phone, Sat Nav etc. (also special "Gaming" cards, suitable for use with PSP's)

The card behaves just like a Hard Disk as used on your PC. Modern operating systems used by PC's & Macs (Win98 SE, Me, 2000, XP or Mac OS8.xx & above) automatically recognise the card when it is plugged into a card reader connected to your computer. This recognition is usually in the form of a "removable drive", which can be read just like a floppy disk or your PC Hard Drive.

In the last 12 months (to Spring 2007), prices have dropped considerabley and many of the current card types have been uprated to hold a maximum of 2, 4 and 8GB. The cost of 128 and 256mb cards has come down to £5 or less and many of the slower but still highly usable cards are being sold off even cheaper!

Caution:

Although it has been widely publicised in the last couple of years, there may well still be fakes littering eBay and the Internet. Generally, the vendors should be easy to spot - stock comes from"offshore" locations i.e. the Far East, the items are on sale for a penny but the post is £15+ etc. Even where the stock is UK based, there is potential that the goods may have been brought here from the Far East in the first place. Just ask yourself the question - 'why is this branded product available so cheaply, when the manufacturer charges so much more?' Answer - it's so cheap because it's fake.

On of the issues with fake cards (and USB drives) is that the original capacity may have been 'expanded', so you pay for 2GB of Flash memory but you run out of space after only 512mb. In addition, these 'expanded' memory devices will often be quite unstable and unreliable - you wouldn't want to commit your irreplaceable images to such devices - would you? Tread carefully!

Files can be read, transferred, saved and modified by software on your desktop or laptop PC or Mac, either through a card reader or directly via a cable link from your device (See your  device User Manual for more precise details).

There a several types of Memory Card available and even within some types, a variation in physical size, to fit into Mobile Phones, MP3 players and PDA's etc. However, the type that you buy will depend on what fornat your device uses. This will usually be clear in your device's User Manual.

The main Types are:

• Compact Flash (Type I and II)

• Memory Stick (MS)

• Multimedia (MMC)- These are now quite commonly used in mobile phones which have MP3 players, cameras and the like included as one or more of their features, These are usually of reduced size (RS-MMC) and come complete with an adapter, so that the card can be used in devices that only accept standard size cards.

• Smartmedia (SM) - this is one of the older formats now available and used by early devices.
  

Secure Digital (SD) - this is one of the most popular types in use by a wide range of manufacturer's devices.

• xD - This type is used almost exclusively by Fuji and Olympus, rarely by anyone else.

Capacities range from a lowly 32mb to as much as 4GB (the size of a small Hard Drive!).

You will find many of these available for sale in the eBay auctions.