Site transforms simple sketch drawings into hard to describe creations that look a bit like the drawing done as a spider web. Printing is done via right-click, but saving is, again, not built-in. Still, scores high on the interestingness scale.
"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."