Tips on giving a big speech
inc.com
inc.com
Here's how the audience perceives what you're doing: everyone will think you spent roughly one third of the speech talking to them, specifically, which is enough to be flattering but not enough to be creepy. The constant movement of attention means you keep moving [+] and don't stare at one person for the entire speech. Your audience will come away with a feeling of closeness and emotional rapport because you were "listening" to them during the speech via your proxies.
+ Don't give a speech seated or standing behind a podium/lectern: weak speakers have a tendency to hide, and the body language tends to come across as fidgeting even when it isn't.
Definitely move around.
Also, people forget - first and foremost, you've got be entertaining. If you're informing but not entertaining, people will tune out. Energy levels higher than normal. It's hard to have too high energy so long as you're not out of control. It's very easy to have too low of energy. Rarely has a speech been bad because the talker was too enthusiastic (I know there's memorable counterexamples, but they're really truly the exception).
Very few people even have the capacity to cross the line between "enthusiastic" and "Ballmeresque".
Even then, many of the exceptions only look silly on video, which is naturally out of context. Howard Dean seemed way too enthusiastic in this clip (http://www.youtube.com/watch?v=D5FzCeV0ZFc) but from the crowd itself it was a lot different (http://www.youtube.com/watch?v=KQh0BEUlJWY).
Here are a couple examples (from the same guy - most of the winning public speakers seem to now professionally coach speakers for a living and don't share their speech videos online):
http://darrenlacroix.com/2010/06/darren-lacroixs-winning-toa...
# Practice, seems simple but when I don't then it will not be as good as when I do.
# Go early and talk to a couple of the people that will be watching the talk. This calms me down as I now have a couple people on myside. It backfired once when I started talking to someone and they turned out to be a jackass, but I moved onto someone else.
# Use the people I talked to as my eye contact, there now friends I should be able to look at them
# Take everything out of my pockets and anything I might start fiddling with off.
# Slide Remote is key as you can interact with audience better.
# Simple slides - one phrase or simple list is usually best, for tech talks I write a snippet on the slide
# Pause and Breathe, it may seem like a long time since the previous word but its not. This tends to be why people start adding filler words (aww, like...)