This is a printed case with 2 parts:
http://www.thingiverse.com/thing:26887Inside there is a cheap GPS module from ebay, GTPA010, an additionally my pcb includes 2 pins for enable the battery in the vbackup pin of the module and one for the "enable" because I want to keep the module full capacity to use via rx tx with microcontrollers. The datasheet describes 2 interfaces
http://screencast.com/t/teY5OC5N9ry, I bundled both.
And here is a video of the process of making the case:
I found making a simple version of your internals with cuboids allows you to make a nice case very quick! Otherwise is nearly impossible at least with simple tools like Google Sketchup.