I've just started studying mobile web design. The problem is that there isn't any standard and almost every brand has multiple resolutions across their different models. Even the iPhones use different resolutions with different models.
There are some PHP tools available that will determine the mobile phone resolution and redirect the user to the correct mobile web page or swap out the CSS file.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin