I schedule MyBackup Pro (rooted features on) to backup "daily", I also use Lookout to backup contacts, photos, and call logs "daily". I use Clockwork (rooted) to perform a monthly "image" backup of the entire phone. And I use "AppBrain" to create a list of all installed apps to easily recover from the market if necessary.
I have never lost ANY data using the above methods even when resetting the phone to factory defaults. Rooting is your only self protection.
Use z4root to easily root, temporarily root, and unroot.