SageThumbs - SageThumbs is a powerful shell extension allowing to preview enormous amount of image formats...
Squash 2 for Mac - The easiest way to compress and optimize images for the web
Context Viewer - Context Viewer is an explorer extension in the form of a Control Panel applet that lets you preview...
Image Resizer for Windows - Lets you resize images by right-clicking.
Pictus - Pictus is a fast, free image viewer that enables Windows to see thumbnails of supported formats, such as PSD. Give it a spin today!
Resizing.app - Image resizing has never been so simple with free online resizing.app. Convert, optimize, resize images with ease and for absolutely free.