I have always been very interested in new input and output devices, especially ones that break through the barrier of computers / consumer electronics and furniture. The technology is there: all that's left now is a clever marketing concept / protocol in order to exploit the network effect. In other words: make something cheap that everyone wants to have, then do cool things when lots of people have that something.
Two of my favorite examples of output devices that are integrated into the background are at Xerox PARC: they have a fountain connected to the Internet which changes its height depending on Xerox's stock price, and a piece of string hanging from the ceiling that twirls slower or faster depending on the congested level of the network. I think I read about this in Wired: sadly, I can't find any good links about these things.
"But Jurie," you cry, "I do not see how this is related to games! Are you wasting my time, like when you talked about Jorge Luis Borges?"
Of course not.
Ambient output devices are not going to change the way we make games today or even tomorrow, but the potential is there. This site of a company making ambient devices contains the following explanation:
"Some information requires constant awareness. For some it's the status of their portfolio, or the health of an aging parent. Others want to know if their friends are online, the upcoming weather, the score of a game, if the fish are biting, or if there's heavy traffic on their drive home. These are examples of information that is neither worthy of interrupt (push), nor worthy of investing time (pull). This type of information should be glanceable, like a clock or barometer. We call this ambient information, and we've created the technology to deliver it."
With the number of always-on games growing (think Animal Crossing, Tamagotchi, Majestic, MMO games), the potential to use these devices for entertainment is growing.