I stumbled across Edward Tufte's review of the iPhone today.

Definitely watch the video. It does a nice job of illustrating some of the interaction genius of the iPhone. Of course, some of it is classical Tufte - focusing in on the most minute details of a graph that I somehow fail to see until they're pointed out, but it also provides a great illustration of how interfaces like the iPhone's support RIA principles.

It strikes me that although the iPhone (disclaimer: my husband and I each own one and we're big fans) is not a Rich Internet Application, the interactions in the iPhone UI illustrate so nicely the direction that interfaces are going in the RIA realm. As he slides images and weather reports across a single plane, Tufte points out that this is not a stack of images or weather reports, but a series.

This is the toughest point for people to understand about RIA's, I think. The interfaces are not pages. They're information spaces and they're moving about on a single plane. This will require the biggest mental shift on the part of users, although, I suppose I could argue that the advantages and accomodations provided by RIA's make the resulting interfaces that much more intuitive that user mental models that deeply understand this sliding around may not need to be considered.

A bigger challenge is thinking about how we can simulate these experiences. There are some exciting new tools entering the market that will facilitate rapid development. I'll save that discussion for another day.