Most of my work involving rate of speech is teaching my clients how to slow down and vary their pace.
Unless, of course, you’re this guy:
[youtube http://www.youtube.com/watch?v=NeK5ZjtpO-M&w=420&h=315]
His diction and clarity is impeccable! This is motor mouth mastery, I tell you. And I still miss his 1980’s Micro Machines commercials.