A "condescending manner" huh.

That said -

"Cold fusion" is, as it stands, a complete myth.  Anyone saying otherwise isn't talking strictly about cold fusion - that is, one scientist I've read about is claiming that "cold fusion" has been found to occur inside of certain bacteria.  This is, strictly speaking, not cold fusion.  Cold fusion is taking two hydrogen particles (a single proton) and forcing them to bind to one another, thus overcoming the strong nuclear force, one of the four fundamental universal forces (which also include gravity, magnetism, and the weak nuclear force).

The joining of these protons forces one to stablize and become a neutron, thus forming deuterium ("heavy" hydrogen) and releasing a large amount of energy in the process.  If this is occurring in bacteria, it is due to a series of complex chemical reactions, none of which are a nuclear reaction by definition.

Likewise, converting our fuel stocks to hydrogen would be a very, very bad idea.  Firstly, the cheapest source of hydrogen in the world comes from - you guessed it - crude oil and natural gas, where we get our gasoline from.  The other "easy" source of hydrogen is electrolysis of water, which consumes more energy than it grants us back as fuel, as well as requiring vast amounts of water - something we'd all rather drink or use to grow food.

Another reason to ignore hydrogen as a primary fuel source comes from simple organic chemistry.  The three most commonly-seen bonds between chemicals you see in organic chemistry are carbon-carbon bonds (shortened here to C-C), hydrogen-hydrogen bonds (H-H), and carbon-hydrogen bonds (C-H).

C-C bonds are very energetic - that is to say, the carbons involved in the bond are bonded quite strongly, and they don't want to "give up" their electrons (that is, the bond is hard to break).  Once the bond is broken, the resulting carbon molecules are very reactive and will quickly seek to make themselves stable again - typically by bonding with oxygen (creating carbon dioxide).  This reaction is fundamental to the internal combustion engine because even though the C-C bond is very stable, it isn't as stable as a CO2 molecule, and thus the net reaction releases energy, powering our engines and such.

However, C-H bonds have considerably less energy - basically because chemically speaking, hydrogen is "easy" and wants to react with damn near anything.  The hydrogen molecule will readily break from carbon, forming (typically) carbon dioxide and varying hydrogen compounds - including water (H2O), dihydrogen sulfide (H2S), and the like.  And compared even to a C-H bond, a H-H bond is very, very unstable and lacking in energy - that is to say, it doesn't take much to break the bond.

So all of that shortened, basically the C-C bonds found in gasoline, jet fuel, and other hydrocarbon-based fuels contain a much higher "energy density" than do H-H bonds found in hydrogen fuels and hydrogen fuel cells.  And since most hydrogen comes from hydrocracking of crude oil and natural gas ... you're actually taking a high-energy-density fuel stock and converting it into a lower energy density fuel, AND losing energy in the process.

That, and if your car had a hydrogen tank, and it ruptured, you'd be sitting on top of a bomb.  It would cause what's called a BLEVE (Boiling Liquid Expanding Vapor Explosion), where the compressed liquid hydrogen in the tank would see the rupture, quickly escape into the lower-pressure area outside the tank, quickly boil into a vapor, causing a rapid expanion of over 30 times the original volume of the container ... causing a systematic expansion of the original liquid, resulting in an explosion.  Combine that with a spark - any spark - and the whole thing catches fire, and you and your car are thus, quite literally, toast.

I think I should start this blog.  Probably starting it soon.