Code

package me.swagmeneer;

import java.util.HashMap;
import java.util.List;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.OfflinePlayer;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.event.player.PlayerMoveEvent;
import org.bukkit.plugin.java.JavaPlugin;
import org.bukkit.scoreboard.DisplaySlot;
import org.bukkit.scoreboard.Objective;
import org.bukkit.scoreboard.Score;
import org.bukkit.scoreboard.Scoreboard;

public class Messages extends JavaPlugin implements Listener {

	private Scoreboard board;
	private Objective o;
	private HashMap<OfflinePlayer, Score> scores = new HashMap<OfflinePlayer, Score>();

	public void onEnable() {
		Bukkit.getServer().getPluginManager().registerEvents(this, this);

		board = Bukkit.getServer().getScoreboardManager().getNewScoreboard();

		o = board.registerNewObjective("showkills", "dummy");
		o.setDisplayName(ChatColor.AQUA + "Kills");
		o.setDisplaySlot(DisplaySlot.BELOW_NAME);

        saveDefaultConfig();

		List<String> s = getConfig().getStringList("scores");

		for (String str : s) {
			String[] words = str.split(":");
			scores.put(Bukkit.getServer().getOfflinePlayer(words[0]), o.getScore(Bukkit.getServer().getOfflinePlayer(ChatColor.GOLD + "Kills:")));
			scores.get(Bukkit.getServer().getOfflinePlayer(words[0])).setScore(Integer.parseInt(words[1]));
		}
	}

	public void onDisable() {

		List<String> s = getConfig().getStringList("scores");

		for (OfflinePlayer p : scores.keySet()) {
			s.add(p.getName() + ":" + scores.get(p).getScore());
		}

		getConfig().set("scores", s);
		saveConfig();
	}

	@EventHandler
	public void onPlayerJoin(PlayerJoinEvent e) {
		Player p = e.getPlayer();

		p.setScoreboard(board);

		if (scores.get(p) == null) scores.put(p, o.getScore(Bukkit.getServer().getOfflinePlayer(ChatColor.GOLD + "Steps set:")));
	}

	@EventHandler
	public void onPlayerMove(PlayerMoveEvent e) {
		if (e.getFrom().getBlockX() == e.getTo().getBlockX() && e.getFrom().getBlockY() == e.getTo().getBlockY() && e.getFrom().getBlockZ() == e.getTo().getBlockZ()) return;

		scores.get(e.getPlayer()).setScore(scores.get(e.getPlayer()).getScore() + 1);
	}
}