Alright...first off about the tackle. Heres a small list of things I could do to stop someone whos charging me dead in his tracks.
Groin kick. He's building huge amounts of force while he charges, so why not let him experience it for himself in the balls? And don't give me the "BUT GIO LOW BLOWS R CHEAP N GAY LOL". Theres no such thing as a cheap shot because theres no such thing as a fair fight. The guy is probably twice my size in muscle mass, so how is that fair?
Clothes line. This is a bit timing-based but sure, you can clothes-line some poor sucker. This time instead of getting his own force in the balls, he gets it in the throat. If it doesn't crush his windpipe, it will definetly fucking hurt and he won't want to fight anymore.
Evade. Simple and sweet, just evade him and let him keep running. I could evade all day. Though I would eventually get bored and just kick him anyway.
"Acceptance-movement." This is when you "accept" his tackle by moving to the side slightly, gripping the arm and then using the force he built running, turn his elbow the wrong way. That hurts. It hurts a lot. If you don't want to be a dick, you could just turn it into a throw and land his teeth in the pavement. Not sure which is worse, but I'm sure he could tell you after he gets back form the hospital/dentist.
For the record, I'm a member of the Unified Fighting Arts Federation/Association. Our School is one of the best in the area. For those who argue the whole "no experience" thing, as you get up in rank you are faced with more real-life situations.
At every test you have to do X amount of self-defense. For my last test which I took Saturday, I had to literally have people my size and bigger charge at me and TRY to hit me. No stopping, no control, try and break my face with their fists, feet, and a variety of weapons and household objects. I got punched once, was a double round-house and one of them landed in my face. Oh well, I just hit him back and moved on. Nevermind that my lip was bleeding, its only a little bit of blood.
Thats another thing; conditioning. People who train are often conditioned by the teacher so that if they DO get hit in the street, they shrug it off. "Oh, so you like punching me huh? Okay, let me try, its my turn."
The problem with martial arts today is the lack of focus on real-life defense. Just like I described, now that I am a Green Belt (thats belt 6 of 10, 10 being Black Belt) no one fucks around anymore. When I do defense, I get charged at. I also had to do multiple-attacker at my test. E.g. one guy grabs me, another charges from the front, after I deal with them I immediatly get attacked by a knife-wielder.
Now that I am done bragging, I need to admit that yes, sometimes you simply can't defend off certain things. If a guy is holding a gun 10 feet away, give him your wallet. And if he says "I'm going to kill you."...well, you got nothing to lose, run in a direction that it would be hard it aim (if its in his right hand and pointing forward, run to his left or your right, he would have a hard time getting an accurate shot like that, then you can attempt to get behind him, pick up a rock and throw it, do something and TRY to stop him since if you didn't he was just going to shoot you anyway).
At close range..well...remember how Leon said in RE4 "Use knives next time, works better for close encounters"? Thats true. You should focus on getting your body AWAY from the front of the barrel. If its a revolver, put your finger over the hammer on the back if its DA, or if its SA try and squeeze it forward to impair the gun, or on a semi-auto, grip the slider as HARD AS YOU CAN. While disabling the gun you should put your knee in his groin, your head in his face, something to make him hurt.
With a knife...obviously you want to avoid the blade. Accept that you will get likely cut, and with the gun you likely will be shot, try and go inside and grip the knife, stick your right foot in his groin or another vunerable area. STOP HIM. Thats whats important.
And a club...avoid the tip at all costs. Best bet is to jam him so he can't swing out, and if he does theres little to no force behind it to give the stopping power he needs to use on you.
And really...applying it in real life can simply depend on where you live. If your in the city, especially if your female, you want to be able to defend. In fact, I know a woman who worked at a mall and was a martial artist. Once she was heading out after work and some creepy dude tried to grab her and drag her away. By the time the cops got there, they were laughing like hell, cause she fucking destroyed him. A bunch of broken ribs, broken nose, ruptured testicles. She felt bad for it too...I don't know why cause he really deserved it.
So yes, Martial Arts are still a valuable tool. I'll close this long-ass post by quoting the FAQ on our website.
"Why are the martial arts so popular?
The martial arts? popularity comes mainly from the fact that it is not a passing fad. It has withstood the tests of time. It is much more than self-defense skills training. It is a lifestyle of physical and mental training and challenges that encourage an individual to strive to do more and be more. Martial arts? training has proven to develop an individual?s complete mental and physical being coupled with an immovable spirit."