I wrote a simple Konami Code class for actionscript. Create an instance, pass the current stage, add an Event listener and do whatever you want!
var konami:KonamiCode = new KonamiCode(this.stage);
trace('WOO, 30 LIVES!');
the default sequence is up,up,down,down,left,right,left,right,b,a and it waits 1 second per keypress before the user has to do it again