Silva Rhetoricae: A great page for learning about Classical Rhetoric.  Run by Gideon Burton of BYU

Figaro Speech: A blog focused primarily on figures of speech and politics/current events.  Works like a blog, but has some great content on stand alone pages.

Loeb Volumes: E. Donnelly has compiled a list with links to online versions of Loeb volumes, many of which are open access.