I got a very interesting question in from Neil about whether woodworking design and creativity may be effectively limited by one's level of experience in using Sketchup. I decided this is probably a bigger topic than just a comment reply, so I figued I would share my thoughts in a blog entry instead. I'm sure there will be many opinions on the matter. Pardon the length, but there is no short answer here.
To be honest, I don't use Sketchup to conceive of my furniture designs, I it as a tool for getting an idea of what my concept will look like in 3D, and to help me generate a list of materials. I would not advocate using Sketchup purely as a creative design tool, but rather a reality check. For example, I did build one project that I thought looked fantastic in Sketchup, but when completed I found the proportions didn't look as natural as I expected. And on the current wine cabinet I'm working on, I've gotten to the point of completing the bottom carcass thus far, but as a reality check I constructed a mock-up of the slant front top cabinet out of pink foam insulation (which you can readily get at any home store in 4x8 sheets). By doing that, I actually made several further design changed (narrowing the piece, and lowering the cabinet a bit).
As another example of a good reality check, the curved legs in the wine cabinet are depicted in Sketchup as closely as I could approximate them, but the actual curve is something I spent hours drawing out with a fairing stick and french curves to generate my template. These types of design elements (that can potentially become the signature of your design) are likely going to be done freehand on a piece of MDF or graph paper, and just approximated in Sketchup.
So in summary, I think ones expertise in Sketchup can help get a 3D model looking closer to the final product, but should not be the creative mechanism by which the design is conceived. Sketchup is a great tool to build reality checks into the process, and can also be invaluable at ensuring good joinery, but is not the end-all be-all creative design tool in my opinion. I'd be very interested in follow-on comments on this topic, as I assume there may be some differing or alternate opinions out there.