Short hand for visualization is always the must for fast idea exploration, brainstorming to any SEO Freelancer. Of course, you can use your lovely old piece of white paper and a pen, friends napkin or cuffs, or you can sharp your idea on a wall with your graphiti. But in our mobile living we need something reliable.
What if you could do diagramming in your web browser without downloading additional software in spirit of Web 2.0? If you could have an desktop application feel in a web-based diagramming solution? Could be able to add collaborators to your work and create diagrams of any kind: Flowcharts, UI wireframes, Floor plans, Network diagrams, UML diagrams, even your drawing? Try Gliffy. Or Cumulatelabs.
Time spent for idea development returns solid foundation of the idea.