SageThumbs - SageThumbs is a powerful shell extension allowing to preview enormous amount of image formats...
Resizing.app - Image resizing has never been so simple with free online resizing.app. Convert, optimize, resize images with ease and for absolutely free.
Icaros - Icaros is a collection of lightweight, high quality, Windows Shell Extensions
Squash 2 for Mac - The easiest way to compress and optimize images for the web
FastPreview - FastPreview was created in need of a usable ...
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.