Then there's the king of Lucid Dreaming, falling directly into conscious sleep.
Some people never can do this (I haven't yet), but the idea is to wake up during a REM-stage of the sleep cycle, keep awake for some time and then get onto sleep again. In theory, this is the easiest way to keep oneself conscious while falling into sleep.
Also, I've heard that when it ucceeds, it can be really startling or scary. Some have reported hearing a loud noise when the state of the mind changes from awake into asleep... and some have not actually believed that they are asleep, as the surroundings in the room looked just the same as in the room...
Reality checks are also a good way to help one realize when one sleeps. The first aspect of lucid is realizing that you are asleep. Reality checks help... for example, if you close your mouth and nostrils but you can still breathe, you are most likely asleep. Also, if you glance at a paper, it might appear incomprehensible gibberish. Or the text might be something at first glance, then chance into something else. Also, take a look at the clock; if it shows completely illogical times, you are asleep. Other reality checks are, for example, just pressing the light switch and consciously thinking "hmm, I wonder what will happen when I press that switch?" If you think that it'll turn the lights on/off, it'll probably do just that in a dream... however, if you don't know what it does, anything can happen. If this happens, you know for pretty sure that you are dreaming.
Also, trying to deliberately and strongly push one's hand through a solid wall now and then is a good reality check. If the hand meets an object, it's most likely real world, if it goes through it's dream.
There is a very good lucid dreaming instructions page, but it's in Finnish so linking it here would be close to useless. These directions are from there, and they have worked... sometimes. I have yet to master the skill of Lucid dreaming, I don't have lucids even every month to tell the truth. But when it happens... it's really cool and stuff.
Some people learn it by themselves, some never master it... but most people have lucid dream(s) multiple times during their life. MAny people just wake up after realizing they are asleep.
Oh, and about this:
anyways, sometimes when i go to sleep, i dream of say running, and i'm probably in a half-sleep half-awake state, and suddenly i come to a stop and my whole body twitches and i usually hit something hard... what would be the name of that occurence? just wondering...
Sounds familiar. You think of something, your body relaxes, and suddenly you hear a loud "wham" or something like that, something like an electric shock goes through you and you're awake again?
It's speculated that this is caused by a remaining primitive reflex from reptile era. It's hypothized that this primitive part of brain is usually mostly inhibited by higher brain functions, but when you get asleep, the higher brain functions get "separated" from other parts of brain, releasing that part to do things, if triggered. It's also hypothized that this primitive part of the brain interprets the relaxation before sleep as a free-fall situation and reacts by sending "twitch" signal to body as a desperate attempt to catch something. But this, of course, is just a hypothized possibility, it's not even a theory yet.
