Add new image size to media uploader so users can insert into post?

I would like to create an additional size for uploaded images which my users can then “insert into post”. I understand that add_image_size() will add a new image size which I can use in my theme, but that new size isn’t available on the media upload screen.

Is there a way to get new sizes to appear on that screen so they’re available to people as they add/edit posts? I have a tweaky theme that needs more than just the default 3 sizes + original.

Thanks!

Just found a new plugin which seems to do exactly what I described above:

http://wordpress.org/extend/plugins/additional-image-sizes-zui/

Hope this helps someone!