If you want to resize an image but you don't have any image processing software on your computer, there's a web site that will do this for you at http://www.my-i-size.com/. You can upload a GIF, JPEG, or PNG image to their site and specify a new width (they maintain the same aspect ratio in the image), and they will resize the image for you and you can then download it from your browser. It's fast and free and requires no software on your computer aside from a browser.