Just a couple more days and the Pen Tool will be ready to deploy. We are excited to hear your feedback once you get a chance to dig in.Michael Lang commented
I find myself sketching flows often as part of my software design process and have wished often that there was a lightweight online tool for doing this collaboratively with my team (that's spread geographically across the US). A pen feature would probably be enough for me. One way or another, if I could just put arrows on the canvas, I think this would be close enough to a virtual whiteboard for my team, whether they were connectors between the boxes or simply marks on the canvas.