Back from vacation which was pretty blog-less on my part. But now I'm back in the fray.
Omri Gazitt writes about the Web Services Security Kerberos Binding that was published in December. Omri talks a bit about how you really get cross-realm Kerb interop by having this kind of support in Web services. Doing Kerb through an HTTP proxy just strikes me as something that is really cool. But before you throw your hands up in horror that someone is doing security through your firewall, realize that it is Kerberos...this means that the only people who have access are the people you trust.