Many times we come across projects and presentations where the best way to explain a dataflow concept or the user to server interaction can be best explained with a diagram like DFD or UML etc. Here is an online tool that might come in handy.Diagram.ly is an online diagram drawing application which let you create professional looking for workflow, BPM, org charts, UML, ER, network diagrams. Its completely free and requires no login or registration and the let you to save the diagrams locally.
# Go to http://www.diagram.ly/