Room and audience management

Its not just what you say, its also how you deliver your presentation and interact with your audience.

Harvard Speech & Parliamentary Debate Society: The team's web page

Public Speaking Practicum: Course website for Expos 40, a course on public speaking.  The website includes public speaking resources and readings.

Public Speaking & Negotiation Club: A Harvard Business School club devoted to personal development of public speaking and leadership skills. 

Improve Your Pubic Speaking: Harvard Business Review blog post on improving public speaking

Need Help Giving a Speech? : Resources to help prepare for giving a speech

How common is it to write out a script for a talk?: Academia StackExchange question on how to prepare for an academic talk.