However, I haven't actually done it with a participant and am hoping that the workshop I am going to next will embrace it, in fact I just asked them to.

What is it?  Backchannelling.  There is an article about it at http://pistachioconsulting.com/twitter-presentations/ and I would like to find a way to do this with my students.  I'll need to look at our moodle site and see if there is a way we can this.

Here's what I REALLY like to do at a workshop.  I like for the presenter's notes to be made available electronically and I like to put them in one-note and put my own notes along side.  I find it make easier to pay attention and be focused.

I will often put a note on the screen for the person next to me and have even handed them my notebook for a response, but wouldn't it be nice to have a "real" backchannel to discuss the goings on.

And yes when the talk is really bad, I'll go do something else.