A few good tools

Polleverywhere
Know what your students are thinking and learning right now. Bringing interactive social assessment to every classroom is now possible and affordable. Using Poll Everywhere in your school or university, you can increase teaching effectiveness without breaking the bank.

Just another tool to use in the class.

http://www.polleverywhere.com/

Slide Share

Upload and share your PowerPoint presentations, Word documents and Adobe PDF Portfolios on SlideShare. Share publicly or privately. Add audio to make a webinar.

http://www.slideshare.net/

Google Buzz

Today Google has updated Gmail with Google Buzz. Google Buzz is now built into Gmail and Google maps giving the you the option of beginning conversations about the things you find interesting. Share updates, photos, videos, and more.

"There's obviously value with social networking services. It is a phenomenon that's real. But increasingly, it's becoming harder to make sense and find the signal in the noise. This is becoming a large scale problem, a relevance problem. It’s like when we launched Gmail. Today, we're launching Google Buzz, a Google approach to sharing."- Bradley Horowitz Director of product management @Google

http://www.google.com/buzz