How to export iMessages from OS X app onto new iPhone

1. Get /var/mobile/Library/SMS/sms.db
2. It is now exported.

What format do you want the export to be? The existing format is sqlite, so you can convert it to ASCII like so: sqlite3 sms.db .dump > sms.db.txt

For step one, you can jailbreak and then scp, or you can just search your backup folder for the file, no jailbreak required.

If your phone is not jailbroken, look on OS X in:

~/Library/Application Support/MobileSync/Backup/<long_hex_string>/

And, in my case, and according to various web sources, although not in all cases, is named:

3d0d7e5fb2ce288813306e4d4636395e047a3d28

To answer your other questions: Any OS, Free, Successful.

Can you create a Folder Action to empty the ~/Library/Messages folder at intervals?