Diagrams are great for getting across things that would otherwise take an endless amount of time and wearisome explanations. Cacoo will let you come up with as many diagrams as you might want, and these include not only site maps and wire frames, but also UML and network charts.
This tool is: A) Web-based, and B) Absolutely free to use. What’s more, it is a collaborative tool. If you have a technology blog with a friend and he is away for this or the other reason when a diagram requiring the input of both has to be published, a tool like Cacoo will save the day. It will let you both dispense with lengthy emails or phone calls. And in any case, it is very difficult to convey visual information in a non-visual way. That is why being able to collaborate in real time from anywhere is twice as alluring.
As it was mentioned above, this tool can be employed at no charge. As long as you have a computer that is web-enabled and some clear idea of what you have to draw at the back of your head, you will have quite a smooth time.
Cacoo.com In Their Own Words
“Cacoo is a user friendly 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.”
Why Cacoo.com It Might Be A Killer
It is a free tool which has all the basic functionalities one could look for already fully covered.
Some Questions About Cacoo.com
In which ways could collaboration be taken a step beyond? 
