Targeting Markup Languages

I want to develop an addition to my site where I can sell wallpapers. I am a veteran php/SQL programmer and have lots of experience beating my head against code
I spent the past week beating my head, on this project.. reading boards, down loading & trying scripts, download & reading manuals, signed up for Bango, talked to my brother......
I have to admit this has really been a challenge. The truth is I'm not cell phone savvy. I haven't owned one for 5 years. Still I'm not about to give up.

So I think I need to start at the beginning. That is... what is my target? I don't want to learn everything at once. I just need to know what will help me make my next decision.

Here's my question:

What markup languages should I bother with? My brother (he programs cellphones for Motorola) say's most phones use WAP. Does anyone know what percentage this is? Is it large enough to ignore others or should I support a second or third language? Also Since most sales would be from Europe & Asia I would need to focus on the type of phones they use. And since I'm selling wallpapers, I don't think I need to support languages that wont support my art (It could create wbmp images on the fly with php/gd but I don't know if its too small of a market to chase).

Thank you ahead of time for your help.

Statistics:
market share
mCommerce
Supported phones:
http://www.kcell.kz/en/services/wap.html

TBH, 'most' new phones support xhtml MP or mhtml. This is a trimmed down version of
xhtml. This means that you can use colors in your pages and most support jpg or gif image formats.

WML is still around but as you probably know this language is pretty limited. You could check the accept_language of the device browsing your site and create wbmp's if jpg or gif are not supported..

So if mobile browsing does take off in India or part of Asia that are newly caught up in the mobile phone boom, the likelyhood is that these phones will support wml (version) only as the will probably be using phones at the lower end of the market.

xhtml and wml are the only 2 versions of a site you would need for a device. Saying that, as some phones and PDA's can read standard xhtml, you can just include a stylesheet for 'handheld's - though the pages ay get too bloated for them if no modifications are made to the pages on the fly.

My site has 4 versions dynamically created with PHP dependant on the viewing device. It generates xhtml, html, mhtml and wml on the fly...

Hope that helps and please post again if you have any further questions...

jamie, four versions, that's cool!