The Web is exactly that. WordPress Posts could do with a little more cross referencing. To become a cross referencer, a user registers himself a la Gravatar. The user then selects a portion of the post and writes a comment and / or provides a URL for further info. This is then held in moderation. When the blog owner edits and accepts this cross reference, his Gravatar or equivalent appears in a drop box next to the post title. If a reader selects this Gravatar, then all the corresponding portions are highlighted. When the reader hovers over any of these highlighted portions, the cross reference pops up as a balloon. The reader may then read this balloon and / or click on the URL if any. The blog owner can decide in what order the Gravatars are placed in the drop down menu. Another way is to have a left and right arrow on the menu. As the reader clicks on these arrows, the highlighted portions keep changing along with the Gravatar. The blog owner can also let statistics decide the order and maybe keep these statistics private and randomize so as not to foster runaway popularity. Professional cross referencing may come in and make information even more granular.