diff --git a/src/com/google/bitcoin/examples/PrintPeers.java b/src/com/google/bitcoin/examples/PrintPeers.java
index d208dda2..cf3a0d7d 100644
--- a/src/com/google/bitcoin/examples/PrintPeers.java
+++ b/src/com/google/bitcoin/examples/PrintPeers.java
@@ -16,17 +16,24 @@
 
 package com.google.bitcoin.examples;
 
+import com.google.bitcoin.core.NetworkConnection;
 import com.google.bitcoin.core.NetworkParameters;
+import com.google.bitcoin.core.TCPNetworkConnection;
 import com.google.bitcoin.discovery.DnsDiscovery;
 import com.google.bitcoin.discovery.IrcDiscovery;
 import com.google.bitcoin.discovery.PeerDiscoveryException;
 
+import java.net.InetAddress;
 import java.net.InetSocketAddress;
+import java.util.ArrayList;
+import java.util.concurrent.*;
 
 /**
  * Prints a list of IP addresses connected to the rendezvous point on the LFnet IRC channel.
  */
 public class PrintPeers {
+    private static InetSocketAddress[] dnsPeers, ircPeers;
+
     private static void printElapsed(long start) {
         long now = System.currentTimeMillis();
         System.out.println(String.format("Took %.2f seconds", (now - start) / 1000.0));
@@ -52,21 +59,56 @@ public class PrintPeers {
                 System.out.println("-> " + message);
             }
         };
-        printPeers(d.getPeers());
+        ircPeers = d.getPeers();
+        printPeers(ircPeers);
         printElapsed(start);
     }
 
     private static void printDNS() throws PeerDiscoveryException {
         long start = System.currentTimeMillis();
         DnsDiscovery dns = new DnsDiscovery(NetworkParameters.prodNet());
-        printPeers(dns.getPeers());
+        dnsPeers = dns.getPeers();
+        printPeers(dnsPeers);
         printElapsed(start);
     }
 
-    public static void main(String[] args) throws PeerDiscoveryException {
+    public static void main(String[] args) throws Exception {
         System.out.println("=== IRC ===");
         printIRC();
         System.out.println("=== DNS ===");
         printDNS();
+        System.out.println("=== Version/chain heights ===");
+
+        ExecutorService pool = Executors.newFixedThreadPool(100);
+        ArrayList<InetAddress> addrs = new ArrayList<InetAddress>();
+        for (InetSocketAddress peer : dnsPeers) addrs.add(peer.getAddress());
+        for (InetSocketAddress peer : ircPeers) addrs.add(peer.getAddress());
+        System.out.println("Scanning " + addrs.size() + " peers:");
+
+        final Object lock = new Object();
+        final long[] bestHeight = new long[1];
+
+        for (final InetAddress addr : addrs) {
+            pool.submit(new Runnable() {
+                public void run() {
+                    try {
+                        NetworkConnection conn = new TCPNetworkConnection(addr,
+                                NetworkParameters.prodNet(), 0, 1000);
+                        synchronized (lock) {
+                            long nodeHeight = conn.getVersionMessage().bestHeight;
+                            long diff = bestHeight[0] - nodeHeight;
+                            if (diff > 0) {
+                                System.out.println("Node is behind by " + diff + " blocks: " + addr.toString());
+                            } else {
+                                bestHeight[0] = nodeHeight;
+                            }
+                        }
+                        conn.shutdown();
+                    } catch (Exception e) {
+                    }
+                }
+            });
+        }
+        pool.awaitTermination(1, TimeUnit.DAYS);
     }
 }