The flickr.photos.comments.getList method currently returns all
comments for a photo. But some photos have an enormous number of
comments so it would be pretty useful if the call had 'page' and
'per_page' optional parameters the way flickr.photos.search does.
There is apparently already a private call that does this because
flickr photo pages only show a limited number of comments per page
like this one that 6 pages of comments.
http://www.flickr.com/photos/kamoteus/2070209030/page2/