Here is an example of what you need to change.

First, copy product_image_link.tpl to your catalog/template/default/shared/  folder.

In the mutiple_columns.tpl, look for and add comment ( // ) to disable:   Should be line 30
<?php //include $shared_path . 'product_image.tpl';?>

Add this line to enable new image tpl file.

<?php include $shared_path . 'product_image_link.tpl';?>

That will change image to a link.

Any where else you whant to change it, do the same.

I think I'll change make this an option.