At the IA Summit 2007, where I taught a pre-conference course, I was interviewed by Wolf Nöding, an Informationsarchitekt at Spirit Link in Germany who has a series of podcasts called "Women in IA." This 40 minute interview covers the origin, uses, process and future of the mental model method for product design. This interview might be a good link to forward to someone you're trying to convince, if that person has the time to listen --maybe at a brown-bag lunch together with your team?