Reading the above article and the associated comments got me thinking about my own data backup system. I have recently been moving my documents to Google Docs and Spreadsheets, which has a limit of 5000 documents. An added advantage of this is that I don't have to worry about different versions of the documents on my desktop and laptop and synchronizing between them.
I do regular backups of important data onto my external drive and laptop, so I always have at least 2 sets of data besides the one on my main machine. I monitor the S.M.A.R.T status of all my drives using Speedfan and defragment them often. I don't know how reliable the S.M.A.R.T measure is. Finally, I buy a new hard disk once every 2 to 3 years and copy all my existing data to that. Since hard disks at least double in capacity every 2 to 3 years, it is usually large enough to accomodate all my existing data build up across all the current drives.
What strategies do others here on DC employ to protect against future or accidental data loss?