I just finished up a presentation I am to give next week in Houston.  I looked through my collection of quotes and things and found this to conclude my talk with when I turn it over to questions and comments:

If your mind goes blank, don't forget to turn off the sound.

The attribution is hazy.  It probably was from an email received at Microsoft but I don't know who wrote it or when.

Almost all politicians and about 75% of meeting participants could benefit from this advice.