Implementing Multifactor Authentication with Christine Seeman

How do you implement multifactor authentication in your application? While at NDC in London, Carl and Richard chatted with Christine Seeman about what it takes to add multifactor authentication support to your application. Christine talks about all of the great tools that exist today to make it easier to put authentication tools to work. But then the tricky part comes - how do you get your users to take advantage of them!