Diigo really is a great tool! I have always used ikeepbookmarks to keep track of my sites. This tool makes bookmarking so much easier. I've really enjoyed using it. I wish I could just drag my ikeepbookmarks to diigo. I know that this is an option with delicious.

You can use this tool for digital storytelling. The site has a Mixbook for Educators Program which offers: free collaborative classroom tools for creating and sharing personalized Mixbooks, secure online environment for students and teachers to share and edit privately, and an education discount on printed products - (up to 40% off printed Mixbooks for your classroom.) Students can use this to create their own stories or younger elementary classrooms could use it to collaborate and create a class book.

PBwiki is for teachers, students, and parents. It lets you create a simple, secure wiki in about 60 seconds. You can make your wiki public or private. You can also embed video & audio, add tags, RSS, and full page revisions, see who changed what, and automatically reverse any changes. It also has access controls. This would be a good collaboration tool for the classroom.

Bubbl.us is a brainstorming tool online. You can use it to create colorful mind maps online, share and work with friends, embed your mind map in your blog or website , email and print your mind map, and save your mind map as an image. It is free. It would be a good tool for students to use.And it's FREE!

This blogging service is intended for classroom use only. Blog accounts are created by the classroom teacher. Teachers may use this service for professional blog publishing functions, and to manage and publish student writings. The teacher may add students as class users on their blog.

This is a great tool for holding group conversations. It is a "collaborative, multimedia slideshow." You can add images, documents and videos. The creator can leave comments and doodle on top of the media as they comment. The user can then share their voicethread with others. Those who view the voice thread can add comments too. There are numerous ways to use this tool in the classroom!

Myplick is a free service that lets you share, embed and discover presentations and slide shows online. You can upload your presentation documents in a variety of formats such as powerpoint, pdf, etc. If you want to add narration or sound effect to your presentation, you can upload an audio file and have the option to synchronize the audio with your slides. After you create a presentation you will have the choice to either publicly share with everyone or only share it within a private group. You can also find out how users are viewing your plick, for example, how much time people stayed on each slide. This would be a good way for students to share their presentations with others.