Windows Vista - Free Image Resizer Print
There is a new PowerToy type add-on for Windows Vista users. The Image Resizer PowerToy Clone. It is a free open source Windows Shell Extension that enables you to resize one or more image files on the fly by simply right-clicking on them.

This enables easy image resizing on virtually any version of Windows. So far I have tested all common image types (png,jpg,gif,bmp) and it resized them without issues. Download it from here for free.

Watch the video review and walkthrough on how to use this free powertoy