i would highly recommend PPC Pim Backup, which can be found here:
http://www.freewareppc.com/database/pimbackup.shtml
its very easy to use too:
-install the app
-do a full backup (does contacts, tasks, calender, notes, etc.)
-specify where you want your backup file to be located (i usually do it to the storage card)
-do whatever you need to do with the phone
-run the app again and restore from the backup file that you created
whenever i hard reset or flash to a new ROM, i always use this app to backup my stuff and backup the Palm messaging file to restore my text messages
hope this helps