Reduce JPEG image file size

A large image file size can slow down your web page getting displayed. You want to get a small size while also retaining good image quality. For JPEG type images, here are some steps to take:

1. Add a bit of blur, which helps reduce noise
2. Decrease saturation a bit
3. Decrease contrast a bit
4. Optimize the image

Source: Expert Optimization: Five Tips for Optimizing JPEGs in Photoshop CS2