I'm afraid to sync it because there's nothing in the outlook, and it may erase everything
I am not sure exactly what happens when you try to sync an already-synced iPhone with iTunes/Outlook, though I assume it would want to take the data from the PC and place it on the iPhone, and not the other way around.
Still, I would imagine you would get some sort of confirmation before it overwrites existing data.
Not sure what other options you have other than hacking it, finding where the
contacts database is stored on the device, and copying it back to the PC. I don't what good it would do you on a PC though, nor do I know if you can later copy that database back to the iPhone and have it work.
I would call or visit an iPhones store if the data is that critical. Perhaps they have a tool to grab the data off of it.
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Mike