Poll Everywhere

This week I learned about a website that I think could be useful for teachers (polleverywhere.com).  I was excited about this website because I have a presentation coming up that requires some sort of audience interaction at the end.  I'm thinking of having my classmates do a poll, via texting to polleverywhere.com.  I think this could be used in college classrooms, high schools (maybe online rather than texting), or conferences!