Quoted from this site (Picture available on the site): http://www.engadget.com/2007/12/12/tomtom-developing-iphone-gps-module/ The picture does look fake though.
The tomtom one is fake but not too good to be true - there is a real open-source dock connector gps in development at partfoundry.com
That answers my thread over in the tool chain section, but what exactly does the micro controller do?