Mobile websites... from Drupal?

[Mars Guitars]

With the explosion of iPhone, iPod Touch etc I'm thinking that I ought to get into mobile websites. What's the easiest way to do this... I'm using mostly Drupal, is there a module that will help? I understand that mobile sites use xml, but that's all I know! What's my best starting place?

I've just started a new Drupal site Guitar Tuner Guide | All you need to know about guitar tuners! and wonder whether I should 'build in' mobile capability before I develop it too far - or can I just add later?

Ta,
Paul