Disable image 'caption' and 'alternative text' funcionality

Hi,

For the site I’m working on, I would like to simply use the media description wherever a caption would be. This is something I’m fully capable of implementing, but, for my client’s sake, I would like to disable all caption functionality from the admin, to keep things from getting confusing.

Also, I would like to disable the ‘Alternative Text’ field, and simply use the media title to populate the alt attribute.

It looks like it may have been easier to disable captions in WP 2.6. How do you do it now?

Thanks.