LinkedIn and Google Maps mashup question


I have almost no idea what I’m doing, so I’m looking for advice.

I’m building an application that allows users to network with others using their linkedin accounts. The application asks the user for permission to access their linkedin information. It returns their name and city and state. I want this information to be stored somewhere so I can drop a pin on a Google Map for every user that allows this.

What I’m guessing is that every time someone allows access, I should take their information and store it in an XML file, and then use PHP to pull all the locations stored in that XML file and place pins on the map. Does this sound right? What is the cleanest/best way to do this? Thank you!