Two shots (at ISO 1600) combined. One at f/11 contributed the soft background. One at f/32 contributed the sharp focus dahlia. Didn't absolutely need to do it this way, but there was a brick wall in the background that I didn't feel like working around by moving the camera and/or the dahlia (especially since the wall was part of my house). Decided to try this (done by creating a mask of the flower & overlaying the two images - masking out the background of one and the foreground of the other. Obviously needs a tripod and two perfectly registered images. I had to go to ISO 1600 to get the shutter speeds even halfway fast to counter the slight movement of the flower).
Go to http://www.pbase.com/image/47389261 for the start of a four image sequence that demonstrates how this "best of both worlds" image was created - and asks for opinions on the "ethics" (at least so far as it might apply to photographic competitions such as Nature's Best magazine.