Below is a bookmarklet that adds various semantic information to a page you browse and highlights those key terms.
Currently, it uses  whatizit to recognize terms, and embeds aTag data within a "<dbcls:atag>" tag.
Remainder: Sometimes whatizit doesn't respond, and nothing occurs in that case.

[javascript:(function(){var%20d=document;var%20s=d.createElement('script');s.id='DBCLS_annot';s.src='http://purl.org/togodoc/annot2.js';d.getElementsByTagName('head')[0].appendChild(s);})()]