Amazon.com: Geekstory Waterproof Active GPS Navigation Antenna DC 3V-5V, Connectors SMA Male Plug M8030 GPS Antenna 28dB Gain for GPS Module Receiver Tracking : Electronics
AN-13GPS Magnetic GPS antenna | Jablotron
Passive GPS Antenna uFL - 15mm x 15mm 1 dBi gain : ID 2461 : $3.95 : Adafruit Industries, Unique & fun DIY electronics and kits