http://www.reddit.com/r/learnprogramming/comments/17db40/java_sound_file_can_be_found_when_running_from/

TestImageResource.java

package name.marcocirillo;
import java.io.IOException;
import java.io.InputStream;

import javax.imageio.ImageIO;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class TestImageResouce {

    public static ImageIcon createIcon(String path) throws IOException {
		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
		InputStream input = classLoader.getResourceAsStream(path);
		return new ImageIcon(ImageIO.read(input));
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		createAndShowGUI();
	}

	private static void createAndShowGUI() {
		JFrame f = new JFrame();
		try {
			f.add(new JLabel(createIcon("img/smiley-face.jpg")));		
		} catch (IOException e) {
			e.printStackTrace();
			System.exit(1);
		}
		f.pack();
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		f.setVisible(true);
	}

}