A memory card is a great camera accessory in my opinion.  A camera can usually only hold twenty to thirty photos without a memory card.  That's not enough for me!  I bought a memory card when I got my digital camera, and it holds hundreds of photos now.  Depending on the size of the memory card, it can hold from seventy pictures to hundreds.  That makes a memory card a fantastic camera accessory.  When I go on vacation, I like being able to take as many photographs as I can without having to stop and download them.  It's really not fun to have to stop the fun on vacation to download pictures, or to run out of memory in the middle of an important time.  I actually have more than one card to use in my camera, and I carry the extra with me in my camera bags.  That way I can switch the card if I need to and not have to download pictures right away.  I love the camera accessory memory card, because it's so convenient.