[Support for handhelds] is going to be a far worse mess than the mess of browser support for computers. Every manufacturer has their own standard, and there is not even consistency from one device to another from any one manufacturer. Here is the information I have found so far, and my feeling about how to proceed:
1) The future for handhelds will be XHTML and CSS, using a stylesheet designated with the media type "handheld". WAP sites are dwindling (or at least not growing) and the newest handhelds are moving to XHTML/CSS. Phones that are labeled "WAP2" can use regular web sites, not just WAP sites. I know XHTML/CSS sites work great on at least some WAP2 phones like my Motorola V600.
2) It appears that the most reliable way to present the handheld stylesheet is to use the
element since some handhelds don't recognize various flavors of @import or @media, but any that recognize anything seem to be able to pick up a link. [Jonny agrees that
is the most reliable method to use.]