Emerging ambient devices give users a unique way of giving information without having to be in front of a screen. This kind of devices use contextual environment as the front-end. Interaction between device and user is minimal and cognitive efforts to understand information falls dramatically. The following image is just an example: Ambient Umbrella "tells you" when it´s going to rain by glowing a soft light in the handle:
To me, the richness of this kind of products lies in how they´re designed to give information without paying attention to them. We don´t need to stop and start to understand the inputs we are getting from these devices. And this is really important nowadays: As NYT says "Since the 1990s, we’ve accepted multitasking without question. Virtually all of us spend part or most of our day either rapidly switching from one task to another or juggling two or more things at the same time".
The challenge for Environmental Interaction Design is obvious: You´re not designing something to be showed on a screen, you´re designing something that will be running contextually on a handle, hanging on a fridge or wherever and above all, with a low level of user´s attention, always in a hurry.