Image Resizer now also for Mac
Mihov Image Resizer is available only for Windows.
However, my friend has developed a similar program that works under Mac OS X as well. It is far more superior than Mihov Image Resizer, so give it a try.
BatchPhoto can do resizing, adding watermarks (text and/or logos), cropping, adding effects like Sephia, re-touching and more. It can also rename all the photos to suit your cataloging needs.