Not sure if this is the most appropriate place to post this info but I am sure the mods will move it to a better place if need be,
One of the brilliant new features in Lightroom 3 is the ability to make automatic corrections for lens distortion, chromatic aberration and vignetting by using the appropriate lens profile.
Unfortunately, for those of us who use Nikon's brilliant 17-55mm f/2.8 lens, there is currently no profile for this lens distributed with Lightroom.
After searching the Adobe website, I finally found one here:
https://docs.google.com/leaf?id=0B3E...thkey=CNrv2soH
and downloaded it. It works very well indeed.