Not sure if this counts as lucid but I did realise I was dreaming..
In the dream I was sitting by a computer in a strange place. There was a guy by another computer right beside me, and I did something on the desktop (as in where the icons are, not the desk the computer was on). I clicked dragged the mouse and the picture on the screen turned. At first we thought it was some graphic card feature. I then notice the guy next to me is playing with an interactive screensaver. And soon I realised that what I did on my computer was a controllable screensaver as well.
Soon I was in the screensaver exploring a old house full of furniture and gadgets, and I was controlling the camera.

This is where the dream turned lucid.. for no apperant reason I just realised that I was dreaming and a rush of excitement struck me. I wouldn't say that the hallway I was in was as clear as real life, but it was a bit more detailed than normal dreaming I suppose. I then tried to do everything I could think of like a kid who just got into an amusement park. I supose trying to jump really high would have been impossible since I wasn't me, I was still this invisible flying camera. Strange. I woke up almost very soon though ..

This is probably my second or third realisation I was dreaming.

In my first lucid dream I decided to try and fly, but I couldn't let go of the heavy plastic bags in my hand witch weighed me down. Even though I was thinking how stupid it was that I wouldn't let go. "Their not important, LEAVE THEM!" - nope