Ever wanted to draw a diagram, flowchart, circuit, mind maps or any other drawing digitally for your classroom. Diagram.ly can be of great help to us teachers. Though there are so many tools freely available on the Net, this one is really easy to use and fast.
You can draw almost any kind of rich colorful diagrams online using this free tool. You just need to drag and drop the images/clip arts to the canvas and adjust them according to your requirements. The diagrams can be exported to a variety of formats like jpg, png, gif, pdf etc.
Other Similar tools
http://creately.com: Another online diagram creating and sharing tool. Supports 23 diagram types
https://cacoo.com/: online drawing tool that allows you to create a variety of diagrams such as site maps, wire frames, UML and network charts. Cacoo can be used free of charge.