Cacoo – Create diagrams online Real time collaboration.
This is a pretty slick online wireframing tool that I’ve used in a few recent projects with my team. Fast, easy to use, a couple of quirks just to keep things interesting, and solid collaboration functionality with a free trial.
Golgafrincham 
Feb 04, 2012 @ 14:33:22
Cacoo looks like a great tool, I personally use Creately diagramming tool for my diagramming needs. Have to admit though that there are quite a few online diagramming tools coming to the market.
Feb 04, 2012 @ 15:05:59
Agreed… I like to try a bunch, get my team working with whatever I vet, and see what sticks. We’ll add Creately — it does look good.