Smush your images and Save bandwith
Yahoo released a great tool to optimize the images. And it’s named smushit. Smushit increase web performance easily. Optimizing images by hand is time consuming and painful. Smush it does it for you. It has 3 modes of operation.

1. You can give it the image URL and it will optimize (smush it) and give you the image and the result savings.
2. Upload your image and it will do its trick.
3. Install a browser plug-in. So while you are in a web page you click this icon and smush it will analyze all the images in that page and give you the smushed results. If you have firebug installed the smushit icon will be right next to it. The smush it browser plug-in currently works in Firefox only.
Smush it will also convert GIFs to PNGs for better optimization. It’s simply great and easy and has made my life much easier. Thanks to Yahoo team.