I hear about a number of ideas passing around that are quite popular, but don't have any basis in fact whatsoever. Please stop telling me these stories. They are not true, and repeating them will not make them true.
Water cannot be made into a fuel. It is a low-energy compound, fundamentally. Hydrogen, which water contains, is high energy, but the only way to extract the hydrogen from the water involves injecting a lot of energy into it. So water is, at best, a store of energy, not a fuel.
There is no pill that will change water into gasoline, and there is no carburetor that can "burn" water. Yes, I understand the temptation, what with gasoline costing several dollars per gallon and water so cheap as to be practically free. Wishing will not make it so.
Cold fusion is the idea that you can have all the energy glories of nuclear fusion without the high temperatures and energy-expensive containment. Supposedly, this happens at room temperature, which is far below the temperatures involved in hot fusion. (Hot fusion basically copies the conditions in the sun -- absurdly high temperature.)
However, for all the buzz, it has only operated once, and no attempt to reproduce it has worked. Generally in science, when results are not reproducible, this generally means that either the first experiment was in error (such as having contamination that the performing scientist was unaware of), or deliberate fraud is occurring. This would not be the first time that somebody got a result that nobody else could copy.
Again, the temptation is obvious. Cold fusion would make it worthwhile to electrically hydrolyze water for fuel and would power entire cities with no pollution.
Science Teaches Morality
No, science is amoral in that it might show you the basic principles, but doesn't give you any guidelines in how to use them. Nuclear fission is identical in the atom bomb and the nuclear-powered electric reactor. One is clearly peaceful, the other is clearly a weapon of war. But both operate by the exact same principles.
Morality is left to the philosophers. Do it well, and get a society that is a joy to live in. Do it badly, and get a miserable hellhole.
Decelerating Speed of Light
Creationists, shown proof that certain stars are so far away that we could not possibly see them if the universe was as young as they say, try to escape this by claiming that the speed of light has been exponentially decreasing since the birth of the universe.
This does not work. Theory has implications in science, and a faster speed of light in the past would affect certain things in the present. No decay has been noted in the present, suggesting a certain curve, and if this curve is true, then there are some clusters of stars that prove the universe to be, under this model, no younger than 4 billion years old.
The theory of light being created already halfway to earth works functionally, but is unsatisfying for two reasons. One, it makes God out to be a liar, as he's showing light from a star that never came from the star. Two, it opens the problem of "Last Thursdayism," in which the Universe was actually created last Thursday with signs of being older, or the more extreme version in which the universe is ten minutes old. Clearly, "Last Thursdayism" is ridiculous.
Creationism may work as a religious belief, but it is so painfully obviously not science that it's not even funny. Yes, I understand you'd like science to back your religious beliefs. If you want it to be a scientific theory, it has to make predictions of some kind.
Some people distrust doctors and other medical professionals. They're expensive. They talk in a jargon-y fashion. In the past, many of them had bad attitudes from the admittedly impressive training they went through. (I went through the college from hell, therefore STFU and do as I say, peon!)
So instead, these people try to relieve their medical problems through "natural" treatment. Unfortunately for them, they clearly don't know what they're doing, have a major fetish for "natural" treatment, which mostly involves random herbs and half-baked theories that don't really make sense.
Now herbs can be a valid part of treatment, since plants do contain compounds that can modify bodily chemistry. Most existing medications are indeed based on earlier herbal ones, with the active ingredient isolated and refined to avoid side effects.
But the theories are often patently ridiculous. Feeling funny? It must be your intestines "auto-intoxifying" itself with your own poop, which they go on to describe being backed up between 4 and 40 pounds of (which would probably kill you from the infection) and how only an herbal enema (with their patented formula, of course) can rescue you. You will feel so much better afterwards. If only because you were so embarrassed before.
"Toxin" is commonly abused in their parlance, and pretty much anything that they don't sell is labeled as a "toxin." Their theory of "whole body treatment" is also incredibly odd. Your toe is broken, therefore...we must mess around with your sinuses. Yes, of course, it is so obvious.
The government has secret funds for you that you can access by....
No, they freaking don't. It doesn't even logically make sense. Where would this magical money have come from, and if it's really rightfully yours, wouldn't it be easier for them to just give it to you, or discount your taxes?
Enlarge your penis/breasts
Ah, this common spam. Apparently, a number of men feel dissatisfied with the size of their genitals, and a number of women feel disappointed in the chest department, so along comes these companies to send a bazzillion emails to convince them that their pill will help.
A blogger actually tried ordering one of these pills. It was a sugar pill that came with an instruction book explaining exercises that any decent physiologist could have told you how to do for free. The exercises give you, maybe, one or two extra inches through tissue stretching.
A Soviet scientist once did an experiment that he claims changed a bucket of water into a polymer-like substance. He further claims that a bucket of water poured into this "Poly water" becomes more of the same.
Of course, just like the cold fusion above, no one else could replicate it, and signs pointed to contamination in the tubes used during the experiment. There are some glues and slimes that, when added to water, might explain the polymer-like behavior.
That there are other explanations does not deter some people from claiming that this is actually a brilliant discovery that "science" is "suppressing" for the glory of "capitalism."
And even if this were true, this would only lead to the eventual doom of the earth if somebody carelessly knocked over the bucket into the drain, which eventually leads to the ocean...
But wait, there's more
There are others, but I lost them when my internet connection cut out and I don't feel like retyping them. This article is long enough already.