Rotate your media
so that you always have at least one backup copy from the previous backup. Many will use daily tapes, backing up on Monday to the Monday tape, Tuesday to the Tuesday tape, etc. That way, if you have a failure and your most current backup is bad, you get another shot with the one that's a day older.
Laptop Computer Data Saved: A sales rep for a large multi-national firm returned from an extended trip, having dutifully entered all of his call details in a database on his notebook computer. His first day back in the home office revealed that his data collected over the past three weeks was not available. His IS department could not find the data, and issued a new notebook computer to the sales rep, but decided to check around for someone who could retrieve the data. Internet Desk was called and the data recovery process began. Since the information was so time critical, the DataICU worked around the clock and into the weekend to finish the recovery and made the files available via ftp in time for the Monday morning sales meeting.