How to load and show comments with AJAX instead of pagination?

Is there a plugin that displays comments like this:

http://img541.imageshack.us/img541/6541/47905634.jpg

when the user clicks “read more”, older comments are being appended to the list with ajax.

It looks like Lester Chan has created a plugin that creates pagination for comments. Take a look at WP-CommentNavi 1.10

Lester Chan has created many good plugins.