The more people see of you, the more they trust you. The less they see of you, the less they trust you and thus your ability to influence others drops significantly. Here, U.S. Presidential hopeful, Texas Governor Rick Perry speaks at a recent event utilizing a Plexiglas podium. This is an increasing trend - particularly in political circles - and it's a good one. If at all possible, use a Plexiglas podium/lectern. A similar tactic is one with thin, central beam - as this also affords a similar amount of visibility of the speaker/presenter. When the lectern is a conventional solid one, a lot less of the presenter is visible - and trust in what is said is significantly reduced. This is especially true when the solid podium is relatively tall or when a speaker is relatively shorter. As a speaker, leader or teacher - you need every advantage in influencing the audience. Knowing the environment in which you'll be speaking and if necessary, altering it in advance will significantly increase your success. Don't neglect this one.