Looks like sonofusion is going to have some competition. Researchers at UCLA have succeeded in producing a fusion reaction on the desktop using a "pyroelectric" crystal (i.e., a crystal that produces electricity due to temperature changes). The crystal fusion technique is less exotic than sonofusion, but also (apparently) less controversial. The report of the desktop fusion reaction appeared in Nature; as usual, the article itself is subscribers-only, but supplemental material (including two mpeg videos) are freely available.

The design of the "reactor" is startling in its simplicity: a small pyroelectric crystal (lithium tantalite) rests inside a chamber filled with deuterated hydrogen. Warming the crystal from -30 F to 45 F results in an electrical field of about 100,000 volts across the crystal, which is then concentrated by the insertion of a metal wire tip near the crystal. The result is a neutron flux over 400 times background, about 1,000 neutrons per second -- a characteristic sign of fusion.

The amount of energy coming from the reaction is much lower than the energy used to produce it, so this is by no means is an indicator that limitless fusion energy is just around the corner. Nonetheless, this is a simple way of producing a neutron flux, useful for a variety of tasks, from scanning luggage at airports to tumor removal to microthrusters for tiny satellites. And while it's not likely, the possibility that this breakthrough could eventually lead to energy production can't be ruled out.

Decent write-ups of the story can be found at Nature News, the Christian Science Monitor, MSNBC, and WBCSD.