do you already have back up software? if not try using microsoft myphone. it will back up any thing pertinant to you, including contacts texts call history and any pictures saved to your device. its simple and free. there are better apps out there, but this works just fine. and over the air. you dont have to plug in or save it to your card. its saved on a microsoft website.
site:
http://mobile.microsoft.com/myphone/en-us/default.mspx