Actually, I'll beg to differ, on all the responses so far (at least, the ones that I saw before beginning this post). There's a possibility that's gaining steam in the physics community.
Have you ever heard of cold fusion? It's the idea that you can carry out successful fusion reactions... at room temperatures. One form, in fact, is looking promising for future employment.
It's called sonofusion, or bubble fusion. It only needs a vat of heavy water, a neutron gun, and some ultrasound equipment, and it works like this:
When you start out with your vat of heavy water, you "seed" (called nucleation) the water with neutrons. Very, very small bubbles form around the neutrons. At this point, the ultrasound is induced, and the vibrations cause the bubbles to expand to almost a millimeter in diameter. Once the ultrasound is removed, the bubbles implode. When they do, however, they produce temperatures in upwards of ten MEGAKELVINS - that is, about as hot as the center of the sun. Furthermore, the pressure becomes phenomenal - a few hundred million times that of the pressures found in our atmosphere, and it's all within these tiny bubbles.
Nowhere on Earth have these temperatures or pressures been seen before.
When these conditions are met, the deuterium atoms in the heavy water undergo fusion, releasing energy. The energy released takes the form of light, called sonoluminescence. In effect, you can produce a star within a jar.
Now, there are some drawbacks to this form of energy. The first and foremost is that the experiment is hard to duplicate - certain parameters, such as the frequency of the ultrasound and concentration of heavy water, make it a very finnicky reaction. Also, it's not a very efficient reaction. Currently, scientists only get about a 10% return on energy - that is, they only get back 10% of the energy we put into generating the reaction. Until it reaches the break even point - the point at which we get back 100% of the energy we put into it - sonofusion won't be a feasible source of energy. This is why fossil fuels and nuclear fission reactions are attractive - put forth a little bit of energy, get a lot of return.
If we could get this to work, however, it would solve our energy problems. Water, as you know, is rather abundant on our planet - it covers 70.1% of our surface. We could even use salt-water, and deuteriated water is found in the ocean. This reaction could be carried out at room temperature, which eliminates costly containment, cooling, and controlling systems. Also, it produces only a very, very small amount of tritium - a radioactive form of hydrogen - that decays FAR more quickly than the traditional waste from fission reactions. If we could employ it, every house, vehicle, plane, and boat could have a portable fusion reactor that is quiet, cool, won't blow up, and needs it's fuel changed about once every six months.
Like I said, our energy crisis would be solved - if only we could get it to work like we need it to.
Hope this helps!