If you have NOT jailbroken yet do this.
1. Backup phone in itunes.
2. Jailbreak
3. Restore backup. (when you first launch itunes make sure you cancel the sync so it doesnt backup over your old backup)
if youve already jailbroken and lost facetime and MMS do this.
1. Restore firmware
2. Setup as new phone
3. BACKUP in iTunes
4. Jailbreak
5. Restore backup
The main thing here is that you have a backup of the phone from BEFORE you jailbroke it.
1. Backup phone in itunes.
2. Jailbreak
3. Restore backup. (when you first launch itunes make sure you cancel the sync so it doesnt backup over your old backup)
if youve already jailbroken and lost facetime and MMS do this.
1. Restore firmware
2. Setup as new phone
3. BACKUP in iTunes
4. Jailbreak
5. Restore backup
The main thing here is that you have a backup of the phone from BEFORE you jailbroke it.