This document provides a list and description of the top 20 free Web 2.0 tools for teachers and librarians. It describes tools for productivity, online publishing, communications, virtual communities, media sharing, blogging, podcasting, wikis, and teaching and learning. The top tools include Google Apps for Education, YouTube, Ning, Polldaddy, Shelfari, SlideShare, WordPress, Podomatic, Wetpaint, Flickr, Second Life, Picnik, Zamzar, del.icio.us, Dimdim, Scribd, ScreenToaster, MediaFire, Animoto, and WiZiQ.