As I just said, now and then as these things roll up out of the blue for maybe a couple of days or nights then go away again so when the activity is high you get a good chance of seeing them. You have to be patient and have plenty of time to look for them as they are there! I have seen hundreds of them having captured at least 12 really good pictures. I have seen black triangles, black disc's glide across the sky making no noise at all. Easter weekend 2009 I saw an Orange round ball like object just glide across the sky about 500 feet up making no sound with not a worry in the world. Dam battery for the camera was charging so I missed a great pic arhh... If your not looking in the general direction you probably wont notice the grey discs as the colour of the discs are so close to the sky colour during the day they just blend in. I have seen them stationary at night, red and white lights spinning at incredible speeds in the centre of a disc shape as the reflection of the lights give an outline of the shape of them! They make zig zagging patterns in the night sky when they maneuver at incredible speed leaving a yellow and orange glow from there maneuver. No plane we have will get anywhere near these things. I know what stealth bombers look like and have seen one come into land at night and they look weird with their cut out wings, but they still make a jet noise. Even though it's a muffled sound they make, they are still a conventional plane. I have seen a round object across the night sky block out the stars when I'm star gazing and that is a real unforgettable sight. Some of them are not very big, looking around 30-40 feet in diameter. I kid you not they are there so if you want to see something that really looks amazing keep your eyes open to the skies and you too will see them. All the best and good luck on your search for them.

Alan Ferguson, Acacia Hills NT