There are some great applications to help you with image optimization and compression. TinyPNG is a great example of a site that helps you to compress you PNG's images online for free. They also have a Photoshop plugin that is available for download at https://tinypng.com/.
Another great application to help you with JPG compression is JPEGMini. Head over to http://www.jpegmini.com/ to get a copy for either Windows or Mac OS X.
Another application that is worth considering is Radical Image Optimization Tool (RIOT). It is a free program and can be found at http://luci.criosweb.ro/riot/. RIOT is a Windows application.
Viewing as JPEG is not the only image format that we use in the Web; you can also look at a Mac OS X application called ImageOptim (http://www.imageoptim.com) It is also a free application and compresses both JPEG and PNG images.
If you are not on Mac OS X, you can head over to https...