Lovely Charts is an online diagramming application, that allows you to create professional looking diagrams of all kinds, such as flowcharts, sitemaps, organisation charts, wireframes, and many more... For free if you register.

You can view a screencast here: http://www.lovelycharts.com/screencast.php

This site is designed to provide teachers with a directory of free webtools along with some suggestions as to how they may be used in the classroom. The site lists 194 tools, that's 194 opportunities for you to use ICT in your classroom and all for free!

This is a list compiled for the contributions of several learning professionals who shared their Top 10 Tools for Learning both for their own personal learning/ productivity and for creating learning solutions for others.

Share, play, communicate, organize, move, customize... on a free online desktop. Looks good, easy to use and fast.

SlideRocket is a web application that provides everything you need to design professional quality presentations, manage and share libraries of slides and assets, and to deliver presentations in person or remotely over the web.

Public launch is coming up very soon. You can request an invitation at the moment.

It looks very promosing. Take a look at the product tour here.

Think.com is a global community for learning. It connects school, teachers and students from around the world to callobrate on projects, share experiences, and build knowledge together. 

Think.com is password-protected and teacher-monintored, no advertising and free.

Dipity is an easy way to make and share interactive timelines about the people and things you care about. 

An example: The American history 1940 - 1989 

Exam Professor is a web-based tool that allows you to manage exams, tests or quizzes (or drill and practice) quickly and easily. From professors setting up their final exam to small businesses training employees, Exam Professor is a breeze to use. 

PodcastPeople.com is a web-based service that makes it easy for individuals and businesses to create, distribute, and monetize video and audio shows over the Internet. There's no software to download and nothing to install, we take care of everything for you on the web. It's that easy. 

Also some schools have their podcasts here. 

At Radionomy you can create your own webradio for free.

You can search, find and listen to Radios.
Create your own radio, it's free !
Share your music or your conten.

Maybe you can make a webradio with your students?