Ajax support

This seems like a great idea. I am having this problem as well (where the captcha is hidden when the page loads, but as soon as my form makes an AJAX call, it appears). Partly I think this is due to the way I implemented my AJAX callback (not quite the drupal way) but still I feel like this is a great idea to ensure the captcha never appears (as long as the visitor has CSS enabled of course).

I have applied issue #1, it worked as expected, thanks.

+1, #1 works for me as well.

Does this put the style element in the body of the page? HTML requires that style elements be in the head element.

I think drupal_add_css() should be used for adding CSS.

Why not use #prefix and #suffix instead of manually adding the 'div'?

If the constantly-changing class is a problem, perhaps it should stay the same for a session or otherwise be cached. Perhaps it could be stored in a variable and changed when the cache is cleared.

This issue needs an explanation of what feature is being added.

I don't understand what this is trying to accomplish. If there is still desire for this, please re-open and provide an explanation.