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.
MysticThumbs - MysticThumbs generates thumbnails of many image types not natively supported by Windows.
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!
Icecream Image Resizer - Image resizer by Icecream Apps is a program to resize images fast and free. Windows version. Free Download.