Hi all,
I want to build a device that can read SMSs stored on a SIM card using an Arduino w/o a computer.
The only SIM readers that I find such as the Ladyada one (SIM Reader)
or commercial ones need to be plugged to a computer.
I basically need to be able to read a numbers from an SMSs stored in a SIM card with an Arduino.
Is there a way to do this? or do I absolutely need to have a computer to read the contents of the SIM?
Thank you all in advance for your help 
You can use the SIM card reader you linked to with an Arduino too, it's just not as convenient because you either have to get the signal before the RS232 conversion or convert your Arduino's signals to RS232 level too.
The reason you don't find such solutions is easy: usually it doesn't make sense to read SIM card on an Arduino. SIM card readers are used for backup purposes in most cases. And an Arduino is not a very good tool for backup purposes, IMHO.
If you look at the schematic for the device you linked to, you will notice that it isn't using any microcontrollers, so the software provided is simply bit-banging the interface to the SIM card. You should be able to use that software to accomplish the same task with the arduino, though it might be a good idea to copy the clock source she uses.
