Audience response systems are gaining some credibility in education (K-12, higher education), corporate meetings, marketing research and professional development circles. Some of you may be familiar with these systems, while for others this could be new technology. The systems were developed to allow forfacilitator/speaker/trainer/educator real time interaction with students/attendees. 
The systems create an opportunity for anonymous or user tagged polling and instant feedback on the topic in question. Here is a screen shot of a poll that was provided by TurningPoint, a leading vendor of ARS systems.
System Configuration
Typical systems include several items:
- Keypads (Radio Frequency or Infrared Technology)
- Receiving station(s)
- Proprietary Software for creating questions, receiving, tallying, reporting results
- Protective Carrying cases
Here is a photograph of the carrying case, software disk and keypads for one of the systems that is offered by Turning Point.
According to Wikipedia audience response systems vary from those for "co-located' audiences to those that allow for remote interaction with the presentation and the speaker.
Why the Interest in the Systems?
Research has been conducted in higher education circles that finds that those educated using audience or personal response systems have higher retention levels than a control group that did not. One study conducted with OB/GYN residents found "Residents who received audience response system interactive lectures showed a 21% improvement between pretest and posttest scores; residents who received the standard lecture demonstrated a 2% improvement (P = .018)".
Other studies have found that active learning has been found to increase enjoyment, participation and retention. See "Physics lecturing with audience paced feedback" , "Audience Response Made Easy" or "Who wants to be..."
Vendors
One vendor, that has contacted me through their PR firm is Turning Technologies with their ARS System called Turning Point. Their technology allows for multiple options since "event organizers can choose any of three handheld units: ResponseCard IR, using line-of-sight infrared (IR) technology effective up to 90 feet; ResponseCard XL, an IR unit that includes a self-paced testing mode; and ResponseCard RF, a radio frequency device that registers responses up to 400 feet away." In addition, their keypads allow for text messaging in addition to simple polling or multiple choice answers, a definite advantage for more extensive essays and responses.
Another vendor that I've dealt with is Option Technologies. I found their technology to be easy to use, alhtough the keypads at the time I used them appeared to be significantly larger than those used by TurningPoint.
I found a review of an implementation of Qwizdom, another system on a recent blog posting at Experiential Learning Center for Excellence in Teaching Learning at the University of Plymouth in England.
Issues to address
Speaker/Teacher resistance to utilization - breaks the flow, uncertainty about how to use technology, hesitation to modify current pedagogical methodology, need some handholding and training, integration with their presentation content
Equipment issues - will the keypads walk or get lost?, maintenance issues, lease or purchase, number of keypads needed, having enough base stations for the number of keypads desired, technology to acquire RF or IR (depends on your anticipated audience size), testing prior to "live" usage
Staffing Issues - who in the training/meeting/academic department will manage the equipment, outsource to vendor
Software Issues - Integrating the software into the appropriate hardware for a given presentation or classroom setting
You can find out more about Audience Response Systems at AudienceResponseInfo.
If you've had experience with an audience response system, please feel free to add your comments on what has worked and what needs continued improvement.
I've updated the PPT - Powerful Presentation Techniques Resource Guide listing to include several new books, blogs, web sites and article links that I've come across or that have been submitted to me. 
