Backchannel is the practice of using networked computers to maintain a real-time online conversation alongside live spoken remarks. (see full Wikipedia article). Backchanneling provides an excellent way to capture audience reactions during a presentation. There are a number of Backchannel services available. I recently had the opportunity to participate in a session where the Today’sMeet service was used.
From the website:
Setting up your free temporary Backchannel space is easy: name the room, choose an expiry period, activate your room. TodaysMeet does not require any personal information for registration purposes. The URL to your room is ‘open’ to any user who knows the address. The URL is not published or distributed in any way by the company, so in a sense, does have a degree of privacy.
Depending on your audience, you may have to encourage the audience participation. In our case, we were using the Backchannel to submit questions to a presenter who was video conferenced into our workshop session. The whole process work well, was free and certainly added to our learning experience.
Give the Backchannel concept a spin. I am sure you will find it a useful tool.