I use a big chief tablet and a number 2 pencil for my concept sketches.
Speling - what exactly are you after? I used to use a Wacom tablet back when I worked on Cadkey, I really loved how I could set it up and it was the only wireless mouse available at the time. I couldn't handle the pen, too small. Are you looking for some drawings of what people have started with or are you trying to see what software will allow sketches so you can import into Pro/E?
We teach marker rendering workshops in that industrial design marker style. What makes this workshop or class so interesting is that it is administered not to industrial designers but to engineers. We do those classes in Photoshop/Illustrator too. We actually have Brookstevents coming in Thursday and Friday. Another interesting thing related to drawing or sketching that is interesting is drawing out your plan of attack. I am talking about the four part boundary and getting your head straight on exactly how your going to model a complex form. Sketching out not like an industrial designer but sketching out the technique. We do that in our one week surfacing workshop and it is truly the best part of our hi-end surfacing workshop.