With page load factor being one of the key elements being focused upon recently, i find this tool i came across a welcome boon for all designers. Being a designer myself i know how hard it is to compress images in photoshop, the end result in most cases is 50/50, the verdict being you have sacrificed image quality for reducing size for web. This is where can be advantageous. Not only does it drastically reduce the size of the images, but also preserves quality.
Check it out guys and if you find it impressive i think it would be worth enough to buy it for $19.