Nicole Sullivan and Stoyan Stefanov are dedicated to making the web a faster place. As integral parts of the Exceptional Performance Team they already shared a lot of crucial information of how to make your web sites faster.
One thing they've been pondering a lot about lately is image optimization for file size. Image editing tools come with all kind of great ways to optimize images for visual quality and file size, but when you look at the image in a text or hex editor you'll find that there is a lot of extra information in the file, for example the name of the editing suite, dates when the picture was created and lots more.
There are a lot of tools that remove this information safely and get the most out of the images without having an effect on their visual quality. The catch is that there are a lot of tools for a lot of image formats, all of them on the command line.
So Nicole and Stefan took their research findings, fired up their code editors and built a web app that does all the optimization for you:
Smushit.com allows you to upload some files or give it a URL. The tool then takes the images, optimizes them and tells you how many bytes you can save. You then get a zip of all the images for download and can replace them on your site.
Here's a video of Stoyan and Nicole presenting Smushit.com at The Ajax Experience in Boston (sorry about the audio):
Yahoo Developer Network