Most of WML is easily portable to XHTML MP, but some features require workarounds. Some features are not supported at all, so if you need them, you should use WML instead of XHTML MP. WML 1.x will be supported in any mobile device that conforms to XHTML MP standards
The standard resolution of most desktop is 1024x768 pixels
S60 176x208
QVGA 240X320
iPhone: 320X480
VGA 480X640
Expect at least 256 colors on a mobile device. Most mobiles support images well—GIF and JPG are universal. As the RAM and processor capabilities are limited, many devices keep a limit on the total size of a page—including WCSS, XHTML MP, and images. 10 kilobytes is the minimum you can expect, but it's best to keep the page sizes as small as possible—less than 30K is recommended. Many users browse with images turned off to save bandwidth costs. Hence our application must not rely on images for navigation or critical operations. Giving proper alternative text to images becomes a must