GSM modules from Ebay work with Arduino?

Projects Networking, Protocols, and Devices
1

I'd like to integrate GSM fetures to my projects, and I don't like using shields because I will make the projects standalone.

Here's two modules I found from Ebay:
http://www.ebay.com/itm/1pc-GSM-SIM900-GPRS-module-development-board-learning-board-/281194207422?pt=US_Radio_Comm_Antennas&hash=item41787b18be
http://www.ebay.com/itm/SIM900-TE-C-Quad-band-GSM-GPRS-Module-Compatible-SIM300C-SIM340C-Socket-/141103479556?pt=LH_DefaultDomain_0&hash=item20da6c3b04

But I'm having doubts that is it anyway possible to interface these modules through Arduino, without external components and/or programming own libraries? I don't want to spend 20€ for a module that I won't be able to use at all.
Has anyone had these working, or know similiar modules that would allow GSM features to Atmega based projects?

2

I've been using the SIM900 modems for some experiments. Be aware that the SIM900A ONLY works in these countries:
http://zapro.dk/div/pdf/20111031145224.pdf - So AVOID it! :fearful:

To use the SIM900-modem, read the documentation for the AT-commands floating around on the internet. Making/Receiving calls, Send/Receive SMS is simple enough.

There is Libraries for the SIM900 for use with Arduino too LMGTFY - Let Me Google That For You

// Per.

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