So far experiments have been done on E. coli bacterial cells, Tobacco Mosaic Virus cells, as well as human and hamster cells.

BBC: Cell infected with HIV

Once a patient's cancer cells are isolated in the laboratory, the gene responsible for producing the antibody is extracted and added to the "tobacco mosaic virus".

BBC: Tobacco 'could help treat cancer'

Apparently they've managed to create some supa' fast memory chips by coating 30-nanometer-long bits of tobacco mosaic virus (pictured above in its natural habitat) with itsy-bitsy platinum nanoparticles.

ENGADGET: Platinum-coated virus to be used for speedy memory