The Fujifilm F31fd does not appear to add anything to the F30 except "Face Detection".
I believe Nikon was the first camera maker that came out with Face Detection about two years ago.
Face Detection appears to be an interesting "gee whiz" feature.
But hardly necessary.
Most people will not use it.
I have not seen any reviews for the F31fd, but here is the press release:
Right now Fujifilm is offering a $50 mail-in rebate on the F30, which is more valuable than Face Detection.
Has anyone seen a review of this camera and is it worth the extra money over the Fuji F-30