I have been asked to conduct an in-service this summer on Web 2.0 tools. Please help me formulate a list of essential tools that I can introduce to these teachers. Most do not use much if ANY technology in their rooms currently so I need to keep it very simple. I want to really drill into five or six things that they will immediately want to use. I don't want to overwhelm them and have them go away thinking they could never use any of it. I plan to introduce them to the Ning of course as a venue for great ideas and possibly Twitter. I want to show them Skype because I've used it so much this year. Would love to get into blogs and wikis. What else do you all think and what clients are most user friendly?