Customisation of a entity view

Hi all

I have been working on a new module and i have got almost everything figured out.
There is just 1 thing that is not working for me. When i try to customise the viewing of the entity. ( I created the entity from the example )
I am not able to do what i want. I or have to create a complete page or i am restricted in what i can put into the hook_enetity_view.

Is there a good example out there that shows a way to customise the view of a entity that leaves the page alone and only customises the area where the entity is.
I would prefer if i could do the customisation in a template file.

Marcel

Update for everybody.. I solved the following way....

  $entity->content['imageurl'] = array(
    '#type' => 'item',
    '#markup' => '<a href="'.$entity->sales_link.'"><img src='.$entity->imageurl.'  BORDER="5" ALIGN="left"></a>' ,
  );

I have customised the #markup's in the hook_entity_view.

Marcel