Adding Arduino shields to the Raspberry Pi can be a very big pain. You end up having a mess of wires running around and setting up the software is a challenge in it's own right.
Here is a simple solution to start using your own Arduino Shields with the Raspberry Pi in under 10 minutes.
Step 1: Parts Needed
Step 2: Connecting the Arduino Shield to the Raspberry Pi
Place the Arduino GPS shield over the Arduberry and mount the Arduberry on the Raspberry Pi GPIO headers. Now turn on the Raspberry Pi.
Step 3: Add the Library
Now download the Arduino GPS library from here:
sudo wget http://dexterindustries.com/files/dGPS_Example_3.... -O /usr/share/arduino/libraries/dGPS_Example_3.zip
Now unzip the library at /usr/share/Arduino/libraries:
sudo unzip /usr/share/arduino/libraries/dGPS_Example_3.zip
Step 4: Upload the Code to the Arduberry
Open Arduino IDE from Start -> Electronics -> Arduino IDE, and open the example from File -> Examples ->dGPS_Example_3. Change the programmer, Tools->Programmer->Raspberry Pi GPIO and upload the sketch to the Arduberry(use Ctrl+Shift+U to upload).