LINK: http://larholm.com/2007/06/12/safari-for-windows-0day-exploit-in-2-hours/
Ouch.
I downloaded and installed Safari for Windows 2 hours ago, when I started writing this, and I now have a fully functional command execution vulnerability, triggered without user interaction simply by visiting a web site.
I have a very hard time understanding how Apple didn't anticipate something like this. One would think that the kind of people who would be excited to download and install Safari on their PCs are the same kind of people who will be instantly turned off by talk of security exploits and other problems with the browser.