Bill Seitz wonders about Wiki and Technorati Tags
I don't use del.icio.us. My wiki ''is'' my bookmarks, and they are more or less tagged by the name of the page they're on.
So one interesting thing might be this : produce a list of the outlinks of a personal wiki, taking the pagenames as tags. Should be quite easy to compare and merge the collections of outlinks under the pages like "SemanticWeb" and "FolkSonomy".
Could also attatch to the bottom of these pages, all the links tagged on del.icio.us with the same name.