More than a decade back, Frank Casanova's demos and talks for Apple, often had a little rap about how computers weren't nearly as smart as the sinks in the airport. The sink knows when you walk up to it and responds by turning the water on. But your computer has no idea whether you're there or not. (I always thought it would be cool if someone could rig Frank's stage computer so that when he walked up to it for the demo, it would squirt water at him to prove it was at least as smart as a sink.)
It hasn't gotten a whole lot better. My computer still doesn't know whether I'm around until I tap the keyboard or jiggle the mouse.
Actually, it got a little better in 2003, with Jonas Salling's Clicker. While the main purpose or the clicker was to allow you to use a bluetooth cell phone as a remote control for Mac apps, one cool feature is that as you walked your cell phone out of range, iTunes would pause and then resume playing when you came back.
Hmmm. Take that further. What if you had a pocket device from Apple that used Bluetooth to signal your presence? (say, maybe one of those long-rumored new Apple toys like, maybe a phone, or next gen iPod or ???) What kinds of interractions might be baked in to the new OS?
Andy Inhatko in InfoWorld, speculates on some of the possibilities.