If you need to create diagrams or charts for your assignments, there are heaps of great online diagram creation tools out the there.
Cacoo is a free online drawing tool that makes drawing diagrams as simple as drag and drop. It has a huge library of icons that you can use to create flow charts, mind maps, site maps and any other form of diagram. Connect them with lines and arrows and easily rearrange them.
Cacoo is also great when it comes to collaboration. It supports multiple users so you can share and edit your diagram with others in real time. You can even export your diagram or embed it into your blog.
Check out the video below to see Cacoo in action.