PrimoPDF (Win)
Convert documents to PDF, for more consistent publishing (and downloading) of documents on your web site. (This facility is built-in to Mac OSX)

Photo resizing utilities
The notes on the Documents page discuss the process for using iPhoto and Picasa to resize your photos. Below are some other utilities design exclusively for resizing photos to make them a suitable size for use on your website:

PhotoRazor (Win)

SmallImage (Mac) 

iResize (Mac)

Resize (Win and Mac)