Nanoogo--This FREE site encourages children to be creative and share ideas. It's a cross between a blog and a digital canvas and formatting is really simple. Users just drag and drop the images and text however they wish. There is also a teacher sign up option, which lets you quickly add a whole class or school. Worth a look.
Symbaloo allows you to set your own desktop to the websites you use most often. I see lots of potential for organizing your classroom computer for display purposes, particularly with young children.
This app ($1.99) will pronounce any word that is typed in on a qwerty keyboard (color coded qwerty available for younger children). Assuming kids can type in a word accurately, this could be very helpful. For iPhone, iPod touch or iPad. Think of it as an e-reader for unknown words...would be very helpful to ELLs and students with word recognition difficulties because it pronounces the word.
Online magazines for children and middle schoolers. Good listing, though there are some costs associated with magazines. Might be beneficial to get 'class' magazines rather than hard copies.
Outstanding video of Kate DiCamillo speaking about her experiences being a writer and reflecting on her writing process. About 10 minutes long but worth watching.