I read an article on Yahoo News about the bedbug epidemic in the U.S. - a comment mentioned diatomaceous earth

as a safe, non-toxic means of killing bedbugs. So I looked up this material and found it is made up of the skeletons of diatoms and is also known as kieselgur (a name I remember that from school) and that it is so good at absorbing water that it dries up the waxy skins of bedbugs and kills them.
The list of other things that diatomite can do amazing: Read on...

from en.wikipedia.org

Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled algae. It is used as a filtration aid, as a mild abrasive, as a mechanical insecticide, as an absorbent for liquids, as cat litter, as an activator in blood clotting studies, and as a component of dynamite. As it is also heat-resistant, it can be used as a thermal insulator.

Diatomite is also used as an insecticide, due to its physico-sorptive properties. The fine powder absorbs lipids from the waxy outer layer of insects' exoskeletons, causing them to dehydrate[7]. Arthropods die as a result of the water pressure deficiency, based on Fick's law of diffusion. This also works against gastropods and is commonly employed in gardening to defeat slugs. However, since slugs inhabit humid environments, efficacy is very low. It is sometimes mixed with an attractant or other additives to increase its effectiveness. Medical-grade diatomite is sometimes used to de-worm both animals and humans. It is most commonly used in lieu of boric acid, and can be used to help control and eventually eliminate a cockroach infestation. This material has wide application for insect control in grain storage.[8]

Its absorbent qualities make it useful for spill clean-up and the U.S. Centers for Disease Control recommends it to clean up toxic liquid spills. These qualities also lend themselves to use in facial masks to absorb excess oils.

It has been employed as a primary ingredient in a type of cat litter. The type of silica used in cat litter comes from freshwater sources and does not pose a significant health risk to pets or humans.

Diatomite (Celite) can be used for the removal of DNA in the presence of a highly concentrated chaotropic agent such as sodium iodide, guanidinium hydrochloride and guanidinium thiocyanate. As with other silicates, the diatomites will remove double stranded DNA but not RNA or proteins. The DNA can be extracted from the diatomites using low ionic strength buffers, including water, at neutral to slightly alkaline pH. Crude diatomites of a uniform size must first be washed in a heated acid such as 5M HCl[10]. Calcination can further improve consistency of the material, while mild caustic treatment may improve adsorption with lower levels of chaotrophs.

The absorbent qualities of diatomite can result in a significant drying of the hands if handled without gloves. The flux-calcined form contains a highly crystalline form of silica, resulting in sharp edges. The sharpness of this version of the material makes it dangerous to breathe and a dust mask is recommended when working with it.

The type of hazard posed by inhalation depends on the form of the silica. Crystalline silica poses a serious inhalation hazard because it can cause silicosis. Amorphous silica can cause dusty lungs, but does not carry the same degree of risk as crystalline silica. Natural or dried diatomite generally contains very low percentages of crystalline silica. Diatomite produced for pool filters is treated with high heat (calcining) and a fluxing agent (soda ash), causing the formerly amorphous silicon dioxide to assume its crystalline form.

Diatomaceous earth Read more at en.wikipedia.org