There's been quite a bit of chatter about SketchUp lately.
It looks like a great design tool and if, or when, I finish
upgrading both my computer and software - and regain
my former abilities with PhotoShop 5.5, replaced by Photo
Shop Elements 6.0, and GoLive's replacement DreamWeaver
CS3 - I plan to tackle SU.

But photo editing software like PhotoShop or PhotoShop
Elements 6.0 can be pretty powerful design tools as well
- if you want to check out variations of an existing design
that you have a digital image of. Here's an example of
what you can do with just a few "tools"

This Neehi 72 piece was linked to in a question in rec.woodworking.
The question was how to cut what appears to be an arch in the
underside of the top.

In the original photo of the piece, the drawer in the center looked
out of place - a big box in the top center. with an arch on either
side of it. I took the image into PhotoShop and by copying areas
of the image and pasting them back in separate layers I could
futz around with moving and changing the drawer.

Just something to consider