On one hand, you can use css like this...
...with this code (using Yahoo's excellent YUI)...

DOM.removeClass(edit_delete_buttons[0], "hidden"); // show it
DOM.addClass(edit_delete_buttons[0], "hidden");    // hide it

...or explicit images like this...

<IMG SRC="blah.jpg" class="padded">

...but it seems like when you hide the image, it draws a blank spot for it where it was put in the DOM.

It seems much easier to do this in JavaScript (thanks to these guys)

element.style.visibility="hidden";  // hide it
element.style.visibility="";        // show it

-- MattWalsh - 03 Sep 2006