Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
According to http://www.apple.com/icloud/features/apps-books-backup.html the iCloud can back up iMessage, SMS and MMS). I've looked through settings and couldn't find anything that would allow me to enable SMS/MMS syncing through iCloud. Is it something that's done automatically in the background, or am I missing something?

your SMS messages are backed up to wherever you have your phone backing up. So if you have iCloud backups on, they are backed up to iCloud. If you have it turned off, they are backed up to your computer when you sync.

So if your reset or wipe your device (or buy a new one) they will all get restored when you restore from your backup.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.