He said text message...
What you CAN do, and what I do with my Nextel BB to text my Air Force buds on VZW, is use the phone email address. All carriers have one, for example mine is:
This is the best way: and cheaper for you. If ou have a BlackBerry, you have a BB Unlimited plan, and therefore you can send emails all day long at no additional cost.
I do it all the time.