Especially on the tooling side. The other day I was riding in the car with Oisin Hurley (Head of Tool Development for FUSE) and we discussed the value of having NOT a lot of screen real-estate, because it really makes you think about what the problem is the user wants/needs to solve and how you can guide the user through that process.
There is a good video-cast available from Apple, which talks about the principles of good UI design for the iPhone. I believe these principles are good principles regardless how much screen real-estate you have. To that extend designing UIs for limited screen real-estate is more a solution than a problem. It creates the right attitude :).
Other opinions? Thoughts?