[cart] Remove "Add to Cart" after adding item to cart

Hi all,

Is there any ways to remove the "Add to Cart" link under individual photo after the user add the item in the cart. It means that user is only permitted to add only one of each item to cart.

The reason I'm doing this because I modify the cart to act as a lightbox so user can add all the photo they want and download it in one go. If there is a such a module anyway?

So far, I'm doodling around the cart module but have no luck.

Thank You in advance.

Edit : I'm able to eliminate the increment and remove the quantity in View Cart page but I'm looking for a way to replace the link on the photo to "Item Already in Cart"