Working tricks to reduce bandwidth usage for a site

http://hostileblog.com/reduce-bandwidth-usage-for-a-site/
http://www.trickytechs.com/lower-the-use-of-bandwidth-of-your-wordpress-self-hosted-blog/
http://www.techrepublic.com/blog/10-things/10-things-you-can-do-to-conserve-internet-bandwidth/