Too bad it’s the bad guys.
As reported on DailyDave and picked up at SANS, Email Battles and elsewhere, there are phishers out there using a botnet (a network of infected "zombie" computers) not just to send emails, but to host the websites and the DNS for their scam.
Imagine what this technology could do for legitimate sites. It could potentially surpass Akamai’s system of worldwide mirrors. You could set up something like BitTorrent that would automatically mirror sites you’re looking at. Getting Slashdotted would actually improve a site’s response!