Kidblog - safe blogging environment for elementary and middle school students.
Edublogs - popular blogging service for teachers where you can also manage student's blogs.
Teacher/Student Creation Tools:
Questgarden - easily create webquests over any topic
Zooburst - create digital pop-up books
Evernote - take notes, web clippings, upload documents and stay organized
Livebinders - your digital 3-ring binder
Box - cloud-storage tool, 5 GB free
Dropbox - cloud based storage, 2 GB free
Sugarsync - sync all of your files from your computer into the cloud and other devices.
Study Blue - what I like to call "21st century studying". Create flashcards with audio and pictures
Easy Notecards - create free online flashcards and share via link or embed on your classroom website.
Engrade - create online grade books, wikis, quizzes, all from one website.
Schoology - create lessons and engage students in a "social networking" interface
Class Parrot - safe way of texting students and parents
Lino - create a sticky-note canvas and share on your class website
Google Voice - give a phone number where you can be reached at or set-up a "homework hotline".
Casa Notes - Quickly make and customize notes to send home to parents or students
Livescribe smart pen - Record audio and notes right into your smart pen and create "pencasts".
Doxie Scanner - Scan students paper work and keep a electronic copy of it into Evernote
Lexmark Printers - With certain Lexmark printers, you can have student's scan their work directly into their Evernote account.
Teachervision - TONS of printables and other resources
Teachertube - Youtube like videos but in a education environment
Classroom Architect: Create your classroom floor plan