SMS mobile messages

[Stephen Barncard]

one way is to have them send you an email message or attachment from 
the phone, which will give you the number and domain.

>Now this is all completely dependent on the service, which makes it 
>especially difficult since number portability is now possible.  What 
>this means is that there is no way to determine from the number what 
>cell phone provider they have.
>
>Derek Bump