Alternative GPS module solution for Nikon cameras: di-GPS Eco Pro-S and Pro-F - Nikon Rumors
Columbus nGPS GPS for Nikon SLRs Cameras
Nikon D90 Homemade GPS
GP-1 GPS Unit | Nikon
Amazon.com : Nikon D5300 24.2 MP CMOS Digital SLR Camera with Built-in Wi-Fi and GPS Body Only (Black) - International Version (No Warranty) : Electronics