it will be gray, cuz it is showing all 3 pics at 33% opacity.

Ok. Could you make that program? Do you know how?

Actually, its not an emulator, it just displays the screen of the NXT that is plugged into the computer. It refreshes every 50 ms.

nxtboy, did you actually try the program i wrote?  it doesn't necessarily show EXACTLY 3 frames at EXACTLY 30% opacity every time, it more layers a crapload of them at closer to 40%, but it has a similar effect to what you want I think... since I don't have that emulator i obviously couldn't test the exact values to make it seem grayest...

Sure
package screenrepeater;

import java.awt.*;
import java.awt.image.*;
import javax.swing.*;

public class ScreenRepeater extends JFrame {
   
    Image background = null;
    boolean bglock = false;

    public static void main(String[] args) {
        ScreenRepeater sr = new ScreenRepeater();
        sr.setSize(200, 200);
        sr.setAlwaysOnTop(true);
        sr.setVisible(true);
        sr.setDefaultCloseOperation(sr.EXIT_ON_CLOSE);
    }
   
    public ScreenRepeater() {
        Thread ssUpdater = new Thread() {
            public void run() {
                AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.SRC, 0.2f);
                while (true) {
                    long time = System.currentTimeMillis();
                    try {
                        background = new Robot().createScreenCapture(new Rectangle(0, 0, getWidth(), getHeight()));
                        temp = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_4BYTE_ABGR);
                        Graphics2D g2 = (Graphics2D)temp.getGraphics();
                        g2.setComposite(ac);
                        g2.drawImage(background, 0, 0, null);
                        setTitle((1d / (double)(System.currentTimeMillis() - time) * 1000) + "");
                        sleep(1);
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
            }
        };
        ssUpdater.start();
        Thread repainter = new Thread() {
            public void run() {
                while (true) {
                    try {
                        repaint();
                        sleep(10);
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
            }
        };
        repainter.start();
    }

    BufferedImage temp;
   
    @Override
    public void paint(Graphics g) {
        g.drawImage(temp, 4, 25, null);
    }
}
Just probably don't try to learn good habits off of how I write code... =P

DJ, I was searching for a way to do something like that, but java's screen-capturing utility basically just captures the whole area including windows in your program, so to do something like that, I would have to make the program constantly minimize and un-minimize itself, or constantly toggle between full size and (0,0), or something like that every time i capture the screen, all which take far too long and/or render the program un-interactable (have fun trying to close it now... =P) So i figured just leaving it fixed in the corner would serve the purpose at least...