In the modern day scenario, testing your website on every browser is not considered to be enough. This is because the web is not being accessed on PDAs, Mobile phone and other similar devices which would have made the web more and more mobile. The websites have to be designed to keep these users in mind too. But it is not that simple.
The Problems
The number of manufactures, and more so, the model of mobiles phones are on a constant increase everyday. It is not possible to test the website for each and every model. What can be done is to make a standardized site for as many mobile browsers as possible. To do this, it is important to keep a few rules in mind.

Minimize the use of images
Take care not to use images to display important information as mobile browsers do not display images. Test the site after the images have been disabled. To make use of the images on forms, use Javascript. This will not cause problems as mobiles don’t support Javascript.

Use less bandwidth
Since the access speed for mobiles is comparable to sub-dial up, the loading time is very important. They need to download the entire source code before the site is displayed. Take care to keep the source code very compact, non-repetitive and simply written.

To do this, it is important to know HTML so that you can write the codes yourself. However, if a WYSIWYG editor is used, run the code through HTML Tidy to make it more compact.

Screen Width
Mobile devices have quite smaller screen as compared to even the smallest computer screen. So, it is necessary to check that your site works properly on small screens too. Tables are specially hard to display on mobile devices. For creation of tables, it is recommended to use XHTML and CSS.

The Rewards
There are a number of benefits of making a website mobile. It is nowadays being used for mobile shopping. Also, people prefer to pay for information or downloads with the use of  their phones instead of credit cards.

It is also a good way to promote your products or services. People now access your website from their mobiles to get things like phone numbers and directions from sites. So, your website must take care to fulfill their requirements.