iPod touch Switch from PC to Mac w/o losing app data?

I have an iPod Touch that I sync with my PC. I just got a MacBook Pro and want to switch how I sync the iPod. I'm not worried about my calendar or contacts because I use MobileMe. Music and video will be easy enough to switch. My biggest concern is application data. I have several apps that record data--including one with a bunch of info about our newborn baby. Is there any way to avoid losing that data? How do I make this switch smooth?

Thank you for all of your help.