Hey guys, I know Tristan and told him about this solution, and decided I'd post here in case any one else had this problem. I downloaded the Psychtoolbox (http://psychtoolbox.org/wikka.php?wakka=HomePage) which is free, and it has a command called KbCheck(). It can read keyboard input at any time even during a endless while loop. I drive a mobile robot using the WASD keys using it. Note: KbCheck outputs a weird key code, use KbName to convert to ASCII.