| There are many ways to "stay up late", late being, after, say, 12 midnight, or the time that your parents go to bed. That's right, you still live with your parents. I don't know about your parents, but mine get rather annoyed when I am up much past 11, though they start telling me off, in hushed voices, wouldn't want to wake up all those sleeping siblings, would we.
Anyway, generally I find that the best way to "stay up late" is to not sleep, though only the biggest moron couldn't have figured that out. However, in most cases the trick is to not alert the parents, and then to have a plan of what to do if, or, indeed, when the parents discover that you are doing things without their permission.
You'll probably be on the internet. That's my guess, though you may like to prove me wrong by immediately removing yourself from this page and going to some game, whatever you feel like. (Personally, since I suck at most games, I enjoy the ones where you can build an army and go around destroying the everyone else's army rather then the traditional, shoot-everyone-who-gets-in-your-way-first-person-shooter-type-games.) However, I suggest that, if you do, you invest in some very good headphones and turn off the surround-sound. Parents hear that kind of thing, as far as I see it, parents don't sleep, they only lie there and wait for you to do something wrong.
So turn off your desk lamp, the sound should be down and for goodness' sake, open a *clean* site so that you can always do the alt+tab thing and your parents don't find you looking at porn again.
Now, I realize that my experience with computers is limited to the one that I am currently tapping on and the ones that I occasionally encounter at the place called school but most have a little button somewhere on the monitor. Press it. Okay, you've probably brought up the menu or some shit like that, so press it again. (n00b!) Anyway, there should be a button that has a little power symbol on it. At least, that's what mine has, and mine has a green light. If I press mine, the screen turns off, and if I press it again, it turns back on.
Have you tried it? Wonderful, this little (green) button is a good friend of yours from now on. If you parents walk into your room while you are up late (or even, maybe, while you are meant to be doing homework) you press alt+tab and switch to that wonderful page full of educational/otherwise beneficial information and then, if you want, turn off the screen.
This way, you can argue that you are saving electricity, or at least increasing the life-span of your monitor by turning it off. And when they turn it on, all they see is good, wholesome stuff.
If you follow these steps you may or may not have just turned yourself from an incompetent fool who needs complete and utter strangers to tell you what to do into a fantastic, all-knowing wonderful teenager who is completely safe from the wrath of the parents. If you don't follow these steps, I don't particularly care, I'm just trying to get my w/us to my name.
Oh, and large pieces of glass between the door and the cathedral-type ceiling should be blackened out. I'm being sent to bed because of mine. | 
