Did anyone see the episode of "That's My Bush" with the lethal injection? That was great...
Oh a more serious note. It's a cocktail of three chemicals, the first one puts you to sleep, similar to what they give to people before surgery, IIRC. The second one does something else, and the third one is a shot of potassium, which stops the heart. You don't feel a thing, except the first needle. Your organs die of oxygen starvation, basically, but you never feel it. It's by FAR the most humane way to die of the choices you have these days. I don't understand why they want to use a video to say it's "cruel and unusal"
Hanging (yes, they still hang people, you have to ask for it in a certain state, I forget which ones), is instant if done right (and it would be, or course). I bet thats the longest 4-8 foot fall you've experienced though. I think the formula for rope length was weight/height in inches to get feet of rope, I forget exactly.
Firing squad is still used in Utah, maybe one other state. Guy just executed by that method not too long ago. 5 shooters, 4 bullets, one blank. The rifles are preloaded, you pick one as you walk in. Expert police markesmen do the job, they aim for a circle on the chest of the blindfolded condemmed.
Electric chair is done in many states, although its being phased out. Nasty nasty nasty way to die. If they forget the sponge, it's even worse. Go read "The Green Mile" for a fairly detailed account on the process, King did his research.
Gas chamber is the most inhumane of all methods. You suffocate from cyonide gas. Terrible, terrible way to die. By far the worse of all available methods. Sometimes takes a good amount of time to die too...and the entire time, you're strapped into a chair, unable to move. If you want a good read on this method, go out and read "The Chamber" by John Grisham. Its an old one, so you should be able to find it cheap. Very similar story in that book to the McVeigh case. One man taking the fall for the actions of himself and an accomplice. He knows it, and he won't give up the other man's name due to his principles. Good, good book. I think I cried at the end of it.
There's my history lesson for the day, kids.
Oh, and if you're wondering how I know all this macarbe information, popular mechanics did a story on it sometime back, and I used it as the basis for a speech I had to do for a class.