Piazza!

Glisser makes presentations interactive – it takes regular PowerPoint or Keynote slide decks and pushes them out live to audience mobile devices, slide-by-slide, as they are presented. It then enables members of the audience to interact with the presenter or each other, and collects valuable feedback. Attendees can also electronically mark-up the slides with notes, and keep them for future reference.

Move beyond clickers to free live polls, quizzes, Q&A, attendance, video & discussions. Add analytics, IM and file-sharing. This is active learning simplified.

Prulu stores, organizes and presents your class Q&A in a simple, intuitive interface equipped with a smart search engine - and it's free. Check it out.