True story: I had a meeting with my (former) manager once and he stopped mid sentence while talking with me to start typing and answer email.
My new manager made it a point to order me a tablet when I transferred from Outlook to OneNote. I resisted using it until he showed me that rotating the screen and folding it flat makes it more like a sheet of paper in front of me in meetings. This clicked - now I can meet with people, they can see my screen (since it's in my lap - they will know I'm not answering mail or anything like that) and I can stay focused on the topic at hand.
That was great, but only for a few months. I still do not like carrying a laptop around, and while our "inking" is very, very good, paper is slightly easier for me to use. So now I have a habit of taking notes in meetings on paper, and transferring to OneNote afterwards. One advantage I discovered to this is I have more time and inclination to enter complete notes, rather than being left with only the notes I took during the meeting. Thinking back to college, this process is similar: take a rough outline in class, and fill in the details when copying and cleaning the notes later. I'm currently taking my tablet to about 75% of my meetings, and using paper for the rest.
The challenge for me as a tester is this: use my own experiences of working with a tablet in meetings, in person, while traveling, etc… to modify test plans. An obvious example of this is getting to all the editing functionality of OneNote while in tablet mode. I don't want to sign off on a new feature which cannot be accessed with only keyboard shortcuts, for instance. Pen users would be out of luck. A less obvious case would be verification of drawing page information if the screen changes orientation while the drawing is happening. Complicated images on a slow machine could take a long amount of time (here, "long" may be more than a quarter second), but that is long enough for a user in a meeting to rotate a screen.
A secondary challenge is to figure out why a tablet won't work in some situations, and help discover if there is something we can do in OneNote to overcome whatever barrier I encounter.
Questions, comments, criticisms and concerns always welcome,