I've never posted about this before anywhere else, but I thought I'd finally share it. I was on a business trip in Las Vegas in August of 2010 and staying at the Trump. I can't remember what floor level, but it was kind of high up. The view wasn't the Strip view, it was on the opposite end, with a mountain view. I had time to kill and since I don't do drink or gamble and am interested in UFOs, I spent hours listening to podcasts and watching the sky, basically UFO hunting. As I was watching toward the mountains, at around 11am, maybe noon, I saw a group of 4 UFOs fly by. They didn't look or act like the stereotypical UFO. It was 3-4 of them, following each other, each the same distance apart. They were black circles, but pretty large. Maybe about The size of a small helicopter without the tail, but not shiny, there was no reflection. They were solid black circles traveling together. They zipped by very fast. When they passed though, as they were moving forward, they very quickly were bouncing up and down as they moved, alternating with the one behind it. As one moved up, the one behind it moved down at the same and so on, but very rapidly, as they were traveling forward rapidly. They moved behind the mountains out of sight pretty quickly. They couldn't have been birds because they were many times larger than a bird, and like a perfect circle shape. They could have been military, but classified, because no aircraft could have made those maneuvers and travelled that quickly. They zipped right by, making the up and down movements. Just wondering if anyone has seen anything similar. Thanks.