Hi Craig,
Interesting post. I think you've unearthed a common but disturbing problem, and it's been amplified in the comments too: Just because we're comfortable using technology to communicate, doesn't mean we're comfortable with others using technology to consume our communication.
I sat next to Clark Quinn at one of the LT11UK sessions earlier this year and he was playing solitaire on his iPad throughout the whole thing. I asked him about this and he said it allows him to free his mind to listen. Sure enough, when a noteworthy point was made, he switched to a note taking app and quickly captured it.
Whilst it's true that people tap tapping on iPads and Laptops may be distracting to a speaker, as speakers we/they need to get over that quickly. Looking at the stats around 75% of students in US universities take notes using a mobile device, and they'll take that into their organisations. We need to keep up. The older ones among us need to learn the new modes of consuming.
Personally, I draw pictures on my iPad during meetings, allowing me to free my mind (a la Mr Quinn) and then note the key points on Mindnode. If I was to share all my meeting notes they'd be a mind map and a picture (and not a good one) of a tree, or a coke can, or whatever took my fancy :)