I have some extensive website that I need to analyze the images and see if they can be optimized. Can any one recommend a good program for this?
+1 for smush.it, if you use the firefox addon Yslow http://developer.yahoo.com/yslow/
it has smush.it built in as part of its optimization arsenal. It offers further file savings in addition to photoshops 'save for web' feature.
I've just tested a few programs last week, on my tests PNGOUT produced the smallest PNGs.
Note that you can get even better results by modifying the image, especially by reducing the number of colors used.
I find that photoshop is lees effective than online tools. If you compromise with 80% quality of image then its size can be reduced to half.
Better way is to take a good resolution image then compress it using some onine tools as suggested here. Then use Office image viewer to resize and compression.
I hope u'll get what you want
For Mac OS X, I love ImageOptim