I had the misfortune of losing half of my photo collection from my first year as a photographer. The culprit: one faulty external harddrive. I was super bummed for a very long time. The only living survivors were photos that were uploaded on Facebook and blog and on some CDs that I gave away to the models (yes, I did this practice a long time ago, but not anymore).
To All Photographers — DON’T LET THIS HAPPEN TO YOU!!!
I learned the lesson hard. So behold my fleet of external harddrives. I make multiple copies of all photo sets into two external HDs, in case one fails, there’s a backup to another one. And another external HD with the Apple TimeMachine program. I recommend Iomega (5 of 6 are Iomegas shown in the photos), has not failed me yet. There are many alternatives to backing up your files such as online backup (Mozy), burning them into DVDs (painful), etc. etc.