A lesson in speaking

I just got an interesting piece of mail from the National Speakers' Bureau. It says that being able to say the following paragraph intelligently and without stumbling is "a prerequisite for any public speaker worth hiring."

She is a thistle sifter. She has a sieve of unsifted thistles and a sieve of sifted thistles and the sieve of unsifted thistles she sifts into the sieve of sifted thistles because she is a thistle sifter.

I'm working on it...