1. Use .gifs rather than .jpgs. GIFs are smaller in size when compared to JPGs.
2.Use 'Height' and 'Width' tags for your images. So while page loading certain place is left for the images and visitor can go through the content while images are loading.

3.If you are using large images, slice them up and make them load as part after part. For this you can use img tags like HSPACE=0 and VSPACE=0.

Optimized image (gif format, sliced to two parts, with width and height tags, HSPACE=0 and VSPACE=0)

4. Use image compression software that reduce image size. Remember, the more you reduce your image size more will be the loss of quality.

http://www.spinwave.com/index.html

http://www.macromedia.com/software/fireworks/

5.If you have lot of images to display, then put them on different pages by linking the pages like 'Next Image >' or something like that instead of a long page with 10 images.

6.Use same image over and over again if you need a similar image. Like if you are keeping a big header graphic on every page of your web site. Then use same graphic to link to all pages on your web site.

7.Flash presentations, mouse overs, animations etc increase page download time. So if you can use html instead of these, go with it.