In several threads here I have advocated for spreading one's travel photos over several SD cards so that if one goes bad, gets lost, gets stolen, etc. the whole trip is not lost. For myself, I use six SD cards for two camera bodies. Anyway, one of the more frequent objections is that this is unnecessary because the poster has never had an SD card fail. Last week I had my first SD card failure. I bought a half-dozen Transcend 8GB Class 10 cards a month or two ago and have been using them since. I had shot a few photos of some children, then started shooting at my niece's wedding the next day. After a few frames, I got a warning, something like "Can't write to memory card." So I did what I always do: released and reseated the card. That worked for another few frames before the message came up again. I pulled the card and swapped in a different one, noting the bad card was #5. Long story short, I later fiddled with #5 in a camera body, then plugged it into a computer. At each try, the card became harder to read. I think had I immediately plugged the card into a computer and copied what I could, I would have recovered most of the shots. As it is, I have only recovered two jpgs and zero RAW files despite trying a number of products designed to recover bad disk drives and bad jpgs. The card is now totally dead. So ... word to the wise: It can happen.