Hello Hak5! :)
I recently read an interesting article talking about how some pictures taken by smartphones can have GPS data, like the location where the picture was taken, in it's header.
Someone developed a tool to display the data. Below is the URL
regex.info/exif.cgi
This got me thinking. Is there a way to get gps data from other mobile applications. Say for instance you are messaging someone on facebook via mobile phone. Would it be possible to tell where it is coming from?