iPad SketchUp - Finger Painting made less messy

When I got my iPad (third-hand generation one--work sponsored), I started exploring the possibilities of using it for drawing thanks to inspiration that I received from an artist friend of mine, Adolfo Isassi.  Both of these were done as "emergent" drawings.  In other words, I didn't know what I was getting myself into until I started to see it take shape in front of me.  That's actually something I tend to do regularly as my drawing/sketching tends to be a form of meditation or a way of keeping myself in motion while I take in information in forums such as presentations, conference calls, meetings, etc.  I used to get in trouble for this behavior when I was in class as a child, but I never stopped.  I wonder how many other people doodle/draw in this fashion....

Both of these were created using SketchUp and my finger was used as the stylus.