Question about iPhone backup..

[mariocapo]

I had an iMac that I synced my iPhone with. I backed it up with time machine and sold it a month ago. I'm waiting on a new iMac release before restoring it with my old backup. I have a new MacBook Air that I never use iTunes with. If I want to put all of my old info from the iPhone 4 onto the new iPhone 5 when it comes out, how should I go about doing this? Can I backup my iPhone to a second Mac with a fresh copy of iTunes? Or do I have to dig into my time machine backup and transfer it to my Air somehow? I have lots of photos and info that I want to bring with me to the new iPhone 5, I'd like to get it all ready to go before the iPhone 5 ships. Thanks in advance for any advice!