A real useful web service for all the designer who want to know what colors have been used on a certain image. You can even download a Photoshop Swatch file containing the color palette of the image.
If you are mostly using only one resample image option when resizing images, then you can change the default option to the option you are using the most.
You don't need Photoshop or some other advanced piece of software to resize a large number of images at once. You can use Microsoft Office Picture Manager which is part of the Office suite.