The SIM808 combines a GSM / GPRS module with GPS technology in a small size card, ideal for GSM application developers.
Raspberry PI GSM Add-on V2.0 is customized for Raspberry Pi interface based on SIM800 quad-band GSM / GPRS / BT module.
Adafruit FONA 808 MiniGSM + GPS, an all-in-one cellular phone module with that lets you add location-tracking, voice, text, SMS and data to your project in an adorable little package.
GSM / Cellular Antenna Quad Band Slim Sticker Type 3dBi uFL
This shield fits right over your Arduino or compatible. At the heart is a powerful GSM cellular module (we use the latest SIM808) with integrated GPS. This module can do just about everything
LinkIt ONE (ARMv7 with GSM, GPRS, GPS and Bluetooth)