As a top level support tech at a large medical institute, I get called to some high level meetings
every now and then for technical issues during presentations. Recently I've noticed when getting called to meetings involving the board of directors, or various committees and panels, that they are using polling software for voting now. This same polling back end has shown up in the Post-Doctoral orientations that I speak at too for getting statistics on the demographic makeup of our audience.
I see this as the future of many of the talks we give as the percentage of attendees with smartphones approaches 100%. There are a few companies building integration into smartphones through apps. One such company I found is Sendsteps (https://www.sendsteps.com/en/). With Sendstep's product, the voting and commenting can be done over Twitter, SMS, or via a website. The advantage of using a third party app in this way is obvious: Remote users can easily participate in the interaction wherever they are.
In the previously mentioned Post-Doctoral orientation, the polls were on education, areas of expertise, nationality, current institutional status, and other relevant demographics. The results were then displayed as color pie graphs on the big screen. With voting the results are displayed either once the voting is complete, usually by the moderator confirming a successful vote in the voting software, or as a live tally showing growing numbers for each choice.
As devices evolve, I think the way we use them for interaction in presentations will evolve with them. We may only be scratching the surface of what's to come.