http://www.splashup.com/splashup/

after a lot of hunting I’ve found a pretty good tool online that gives users most of the simple freedoms designers have through the complex Photoshop software. this tool helps you crop, add type, and compress images based on file size for the web. it’s entirely online based and lets you browse for images from your computer and save back to your computer too.

check it out. go to File, open image, browse, select a photo, go to IMAGE MENU, and type in image size. then when you choose to save it lets you choose the quality (which determines file size).