I can't stand any of the SMS tones that come loaded on the iPhone and unfortunately I've found we can't add new ones
Why in the world would they put this restriction on the phone, it doesn't make sense to me.
Because Apple doesn't want people using SMS, they only included SMS in the phone because they probably couldn't convince AT&T to sell a phone without it.
Along the same lines, why can't we change the email tone at all? That little bong noise is too short and not very loud. I have push email now, except I can never hear it when mail arrives. Kind of defeats the purpose. Also, we get notifications on the locked screen for SMS, calls, and voicemail. Why no email notifyer? I have to unlock the phone and check the home screen to check if I have new emails.
check out taskbar notifier