The iPhone (based on OS X 10.5 Leopard) stores many configuration settings in a property list (.plist file). While these are often text XML files, at times Apple uses a binary plist format. If you are analyzing the file on a Mac, you can easily open (and edit) the file with several programs including the Property List Editor and plutil (to check the syntax and convert between XML and binary).

On Linux, you have several options. You can compile the source code provided as open source by Apple on their open source developer website. Also, I have found a perl version of plutil that works well on Linux.