Images instead of radio buttons or dropdown list? I would like the user to choose the category when he creates a new node content. However, instead of radio buttons or dropdown list I would like to have selectable images, with exactly the same logic. Is it possible to somehow ovveride radio buttons / dropdown lists with options being displayed as images? So, for example instead of a radio button with 'Cars' label I would like to have a picture of a car, then for the next category another picture, etc. Any advice appreciated.
You can accomplish this with a combination of a little JQuery and CSS.  

Here's some starting points


http://codeloaded.com/fullscreen-preview/jquery-image-checkbox
http://aaronweyenberg.com/90/pretty-checkboxes-with-jquery
http://codecanyon.net/item/jic-jquery-image-checkbox/full_screen_preview/676874
http://boedesign.com/blog/2008/06/08/imagetick-for-jquery/


Then use a custom module to load the JS when needed using drupal_add_js() typically instantiated with a hook_form_alter().

Something like this:

/**
* Add example.js to content type 'car' create/edit form for example.module
*/
function example_form_alter(&amp;$form, $form_state, $form_id) {
if ('car_node_form' == $form_id) {
  drupal_add_js(drupal_get_path('module', 'example').'example.js');
}


You can find more examples for detecting different forms and patterns on the hook snippets page.