I've researched ways to record voice to SD card and I have found some articles that have had success with PIC microcontrollers. Is it possible to do this with the ATMega 250?
You would need a library: http://arduino.cc/forum/index.php/topic,118073.0/topicseen.html Where is the sound coming from? Mic? Here is interface options: http://coolarduino.wordpress.com/2012/06/22/audio-input-to-arduino/