In order to disable a textarea (or any other input element), you can:
In HTML, you can write:
<textarea id='mytextarea' disabled></textarea>
From jQuery, you can:
$("#mytextarea").attr("disabled","disabled");
CSS? Is it possible to disable the textarea with CSS?
Here is a hack.
The way it works is this. Whenever the user tries to enter anything, we use jquery to catch the event. Then we tell the event we don't want it to do its default behavior. As I say its a hack but its an effective one in a pinch.