I'm working on an SMS device that is programmed in the Arduino IDE and uses a tiny chorded keyboard for input, a SIM900 GSM module to accept standard AT commands, and a Nokia5110 LCD to display output. I stopped by earlier this evening and Paul (thanks Paul!) helped me debug. I've posted a thread on the Arduino.cc forum http://forum.arduino.cc/index.php?topic=206415 but basically I'm having trouble getting my sketch to run in the tiny 2K of RAM available on the ATmega328.
I'm hoping somebody can help me reduce the memory footprint of the GKOS keyboard library found here http://playground.arduino.cc/Main/GkosMain. I've updated that page to reflect the minor tweaks I had to do to get it to work with Arduino 1.0+ since it hasn't been updated in years. If you have other suggestions I'd be happy to hear them.