It is easy to get SMS messages sent from MCR. 

The first step is to make sure your cell phone number and network are correct in your profile screen.  You can get to your profile by clicking "My Profile" at the top right of your homepage.  

Once you "Save changes" in your profile, a text message will be sent to you with your activation code.

Type that code into the box at the top of any page on MCR and click "activate."  You will see "Success!" once your phone has been activated.