I hadn't heard of this one. "Storm" a worm (bot?) quietly infecting windows machines allowing someone else to take it over at a time their choosing. For nefarious purposes. http://observer.guardian.co.uk/business/story/0,,2195730,00.html
Bots are pretty interesting, just like zombie PCs. Takes a lot of knowlege to set up a botnet like they talk about in this article. I'm not worried about my machine being taken over, I use Linux. Of course I have my own share of issues. Recently read that there are some hackers that are able to install a root kit on Linux machines and use that to infect Windows machines. I don't know how they get the root kit installed, but the reason they don't take control of the Linux machine is that permissions won't allow it, but it allows them to install software(??)