Mikrolelektronika actually has two modules that are similar, the GSM Click and the GSM2 Click. Each one is based on a different GSM chipset (Telit on the GSM, Quectel on the GSM2), but both are quad-band and support GPRS.
The interesting thing about these modules is that they have a full TCP/IP stack built-in, and they even support high level protocols such as HTTP and DNS. Imagine implementing all that in an Arduino with 32K of flash and 2K of RAM... So the workflow for an HTTP request in these modules is actually very simple:
- Unlock the SIM via PIN
- Wait for network registration
- Start a GPRS connection
- Open up a connection to your server:port (ie. google.com:80)
- Send / receive data
- Close the GPRS connection