MightyText and SMS Forwarding
 

Mightytext.net offers a free service which will sync your SMS messages to the web and allow you to remotely send messages out through your phone (using a computer). I'm wondering whether anyone has played with trying to use it as a way to leave your domestic/home SIM back in your house on a charger and syncing with your other phone when you are out roaming around the world. While not the primary purpose of the program, it seems like it could be repurposed for that job.