how do you make an actor move randomly around the world?
   
   
            
public void act()
{
   int xRand = speed - Greenfoot.getRandomNumber(speed*2);
   int yRand = speed - Greenfoot.getRandomNumber(speed*2);
   //where speed is an "int" that you defined as a variable
   setLocation(getX() + xRand, getY() + yRand);
}
public void act()
{
   move();
   int rotRand = speed - Greenfoot.getRandomNumber(speed*2);
   //where again speed is some "int" that you have defined.
   setRotation(getRotation() + rotRand);
}