Considering all the time it took me to rip all my CDs plus the over $1,000 or iTunes Store purchases organized into my 50 favorite playlists and the fact that I have suffered two hard drive failures in the last 7 years, I finally invested $170 in a simple backup.
I use this:
http://store.apple.com/us/product/TR044ZM/A?fnode=MTY1NDA0Nw&mco=MjE1NDcxOQ&p=3& s=alpha
and this:
http://www.decimus.net/synk_standard.php
Whenever I add or edit music, I plug in the portable drive and make a complete backup of my entire iTunes folder. Since the backups are incremental, it took less than two minutes to backup after I added 27 songs today. If I have any problems, I can just copy the complete backup back to my computer and I'm back in business.