like Memory I have heard of some virus that will trash the HD (can't remember names at the moment) and of course there was always the CIH virus which tried to flash your BIOS - didn't always work (but I have seen a box that did have the BIOS successfully flashed by CIH - not good) so in a sense we already have primitve viri which do physical damage to a Pc.

However what I am more interested in.... is the possibility of a virus for protein or DNA based computers.... these are still very much experimental but I figure what happens if we do get these type of computers to work efficiently (a long way off atthe moment) and then get them to the stage where you can inject them into a human (e.g. upgrade your memory - something similar to Johnny Mnemonic by William Gibson if you've read it) ... can you imagine what a virus (either a natural or engineed one) would do... not only to your data but also to a body.

Just some idle musings

Z