Iphone Question; Synching to New PC

My wife would like to synch her iphone (3GS) to our PC. I had to get a new PC recently and she wants to back up her photos, etc on the new pc. Problem is, predictably, when she goes to synch the message she receives is that it will wipe clean the phone in order to synch. Any suggestions on settings or other options to get everything off the phone and on the new pc without cleaning it out first.