To make a website usable on mobile devices. We have to take some simple steps.

• Make the page flexible width and viewable at 300px width.
• Make all Images less than 300px width (thumbs).
• Use less Scripts - Mobile Devices, CPU, is not as fast.
• Use Less Tables and Bullets with Noindent.
• Do Not use Sidebar, Navigation at Top-Bot.
• Make a unique section in your website for mobile sites or use scripts to modify to be presentable. The latter may not give good results, unless you preprocess the pages so that they modify well with your scripts.

Make pages usable in Devices such as Smartphones which has a larger screen and a keyboard. The earlier web enabled small phones may not be practical as screen sizes are too small and no keyboard. Even the Networks need to fully evolve to things like WiMax for a full user Experience. Till that happens, images, pages for Smartphones need to be Optimized a bit more.

try - Opera Mini - Live demo that functions like it would when installed on a handset.