diff --git a/pyad2usb/ad2usb.py b/pyad2usb/ad2usb.py
index f53f21f..887d8d9 100644
--- a/pyad2usb/ad2usb.py
+++ b/pyad2usb/ad2usb.py
@@ -12,9 +12,67 @@ class NoDeviceError(Exception):
 class CommError(Exception):
     pass
 
-class AD2USB(object):
-    on_test = event.Event('testing')
+class Overseer(object):
+    on_attached = event.Event('Called when an AD2USB device has been detected.')
+    on_detached = event.Event('Called when an AD2USB device has been removed.')
+
+    def __init__(self, attached_event=None, detached_event=None):
+        self._detect_thread = Overseer.DetectThread(self)
+
+        if attached_event:
+            self.on_attached += attached_event
+
+        if detached_event:
+            self.on_detached += detached_event
+
+        self.start()
+
+    def __del__(self):
+        pass
+
+    def start(self):
+        self._detect_thread.start()
+
+    def stop(self):
+        self._detect_thread.stop()
+
+    class DetectThread(threading.Thread):
+        def __init__(self, overseer):
+            threading.Thread.__init__(self)
+
+            self._overseer = overseer
+            self._running = False
+
+        def stop(self):
+            self._running = False
 
+        def run(self):
+            self._running = True
+
+            last_devices = set()
+
+            while self._running:
+                try:
+                    AD2USB.find_all()
+
+                    current_devices = set(AD2USB._AD2USB__devices)
+
+                    new_devices = [d for d in current_devices if d not in last_devices]
+                    removed_devices = [d for d in last_devices if d not in current_devices]
+                    last_devices = current_devices
+
+                    for d in new_devices:
+                        self._overseer.on_attached(d)
+
+                    for d in removed_devices:
+                        self._overseer.on_detached(d)
+                except CommError, err:
+                    pass
+
+                time.sleep(0.25)
+
+
+class AD2USB(object):
     on_open = event.Event('Called when the device has been opened')
     on_close = event.Event('Called when the device has been closed')
     on_read = event.Event('Called when a line has been read from the device')
diff --git a/test.py b/test.py
index 369a25c..e659b60 100755
--- a/test.py
+++ b/test.py
@@ -24,22 +24,34 @@ def handle_read(sender, args):
 def handle_write(sender, args):
     print 'write', args
 
+def handle_attached(sender, args):
+    print 'attached', args
+
+def handle_detached(sender, args):
+    print 'detached', args
+
+
 signal.signal(signal.SIGINT, signal_handler)
 
 try:
-    wut = pyad2usb.ad2usb.AD2USB()
+    overseer = pyad2usb.ad2usb.Overseer(attached_event=handle_attached, detached_event=handle_detached)
+    #overseer.start()
+
+    """wut = pyad2usb.ad2usb.AD2USB()
 
     wut.on_open += handle_open
     wut.on_close += handle_close
     wut.on_read += handle_read
     wut.on_write += handle_write
 
-    wut.open()
+    wut.open()"""
 
     while running:
         time.sleep(0.1)
 
-    wut.close()
+    overseer.stop()
+
+    #wut.close()
 except Exception, err:
     print 'Error: {0}'.format(str(err))
     #traceback.print_exc(err)