Free software to consider using in courses

Try to break free from your less flexible virtual learning environments, such as Blackboard, Angel, etc., and use content on the web.  I still keep my grades and tests there though.

Some free programs I am using include:

• Web pages for content, wikis, discussion:  Google Sites
• Videos:  YouTube, Community Clips, Fraps   
• Documents, presentations, spreadsheets, forms:  Google Docs, Prezi
• Virtual Worlds:  Second Life
• Social bookmarking:  Delicious
• Social web pages:  Facebook
• Mind maps and diagrams:  Gliffy, Prezi
• Chat and video conferencing:  Skype, Google Talk
• Classroom polling, surveys:  Poll Everywhere, Survey Monkey, Google Docs
• Photos:  Picasa
• Graphics:  Gimp
• Blogs:  Blogger, Twitter
• Email:  GMail