Content is often the reason users come to your site.
Google is making a huge investment in developing the Ajax approach.
Besides, Weebles are too hard to draw - they just end up looking like eggs, not people.
There are some aspects of the diagram that I wish I had expressed a little more clearly.
Ajax is an important development for Web applications, and its importance is only going to grow.
Ajax isn't a technology. It's really several technologies, each flourishing in its own right, coming together in powerful new ways.
Building technical systems involves a lot of hard work and specialized knowledge: languages and protocols, coding and debugging, testing and refactoring.
But despite the universality of URLs, we often forget that they're not just a handy way to address network resources. They're also valuable communication tools.
I'm not sure that you can say definitively that some roles are better filled by consultants, but I would say that some projects are better handled by consultants.
User-centered design means understanding what your users need, how they think, and how they behave - and incorporating that understanding into every aspect of your process.