Found a pretty interesting thread on a prototype N900 that Nokia had been working on:

http://www.newscientist.com/article/...-illusion.html

Using the touchscreen to create illusions of textures on the screen via electro-static sensors.

Too bad this will never filter down to existing N900 machines I think.. but it seems to be pretty nice technology given that some people (including myself) hate touch screens because of a lack of tactile feedback and not precise enough for the onscreen keyboard taps.

Looks good, but Imagine the size of battery you'd need to power that all day! While we're on the New Scientist website did you see this from the other week?

I wonder if the maemo community could add this kind of functionality to the n900.

I may be wrong, but i believe the electrostatic interface uses less energy than the n900's haptic feedback, because it isn't spinning the motor.

I think it may be related to the nano technology nokia is showing off on conversations.nokia.com. They also showed a demo of future (phone?) technology that can detect smell.