If not, a suggestion I have is to either consider this option, or to force people to enter something in the 'from' field before sending the SMS.
Many of my friends forget that their lj-username isn't logged when they send me a message, and I receive a lot of anonymous texts. If we can log IP addresses of even anonymous users who comment, we should be able to log IP addresses of users who use Livejournal to text. right?
Thanks for your time.