import dbus, avahi, dbus.glib

def __serviceDetected(interface, protocol, name, stype, domain, flags):
	print "Found something"

bus = dbus.SystemBus()
server = dbus.Interface(bus.get_object(avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER), avahi.DBUS_INTERFACE_SERVER)
browser = server.ServiceBrowserNew(avahi.IF_UNSPEC, avahi.PROTO_INET, '_ssh._tcp', '', 0)
listener = dbus.Interface(bus.get_object(avahi.DBUS_NAME, browser), avahi.DBUS_INTERFACE_SERVICE_BROWSER)
listener.connect_to_signal('ItemNew', __serviceDetected)