This is a fantastic tool for feedback. For quickly gauging what your students know, how your audience is feeling or which topic you should address next, Polleverywhere is ideal for the classroom or conferences and has free and premium options.
Participants can respond to your poll via SMS, Twitter or the web. Many schools may not have access to the SMS option due to school policy, however students can still respond by being given a URL.
Polleverywhere is ideal for conferences as almost all delegates would have a mobile phone or iPod touch and speakers can modify or customise their session depending on the mood of the audience.