As for getting people's attention in the same room..there's one guy who comes to mind.. countless times I've been ignored once or twice when addressing him. He could just be watching TV, or have his back turned, doing a chore.. It doesn't really annoy me or anything. I just don't understand it.
On the flipside, he's absolutely anal. Neat freak, organizes everything, makes lists and charts..He's the kind of guy good to have on a camping trip as well. He organizes everything, and never forgets supplies, what foods to have, etc.. Maybe he relies on this stuff to keep anything together, I guess. Actually talk to him though, and you might not get his attention.