Displays popup photo thumbnails on mouseover of links to images and Flickr photo pages.
If FlickrTips is working, links to Flickr photo pages will be underlined in a characteristic "pink dotted underline" to suggest the Flickrness of the links. Regular image links will get a more subdued blue dotted underline. When you place your mouse cursor over one of these links, a thumbnail of the image should appear next to the mouse cursor.
FlickrTips depends on the "wp_head" and "wp_footer" actions which are called by most WordPress themes. Make sure that those two actions are being called in your theme's header.php and footer.php.
Collections aren't yet exposed via the Flickr API. Still waiting!