Using *ist-Ds at lower resolutions

[David Oswald]

A lot of my wife's shooting is for business purposes, and her images are 
displayed at 640x480 or less (approximately).  Givn that she reduces 
them so greatly once they come out of the *ist-DS, I'm fairly certain 
that there is no need for her to shoot at 6mp.  Yet of course she 
wants/needs the best possible quality reductions within the limits of 
reasonable amounts jpeg compression for web display.  Is there any 
advantage to her continuing to shoot at 6mp, or should I teach her how 
to switch to 4mp or 1.5mp?