Best way to poll students during a class by web I'm looking to get feedback from students fairly seamlessly during a lecture. I know that there is a reluctance to raise one's hand (if part of a large audience), and my experience of such polling attempts (as a student) has been to break up the flow of a lecture quite considerably. Personally I don't want to get into a high-school teacher role of trying to tease out responses to questions so providing a platform for quick and semi-anonymous feedback would be useful.

But how to achieve this? Crucially most of the students are unlikely to have laptops, but are almost universally going to have smart phones. I don't want them to be struggling to take down the URL to a poll from a lecture slide, or having to log into some terrible VLE like Blackboard in order to get access to a link. QR codes could, in theory, be used to provide a link - but QR codes don't seem to be used much by casual users these days...

The reason for a digital rather than paper poll is that I can immediately respond to the results. Most of all I'm looking for as seamless an integration as possible into the lecture environment.
Poll Everywhere is a good, easy one. It's free for 25 responses per question. Students can respond on their smartphones, laptops, or even old-school cell phones via texting.

Plickers is another good one. For this one you print out the possible responses and hand them out. Then students hold up the card corresponding to their answer. You use your smart phone camera to scan the room and the app calculates the responses.