I've seen some pretty awesome presentations when attending technology conferences. Many of them were by incredible presenters like Ben Forta and Hal Helms. I've also seen some really, really terrible presentations where the audience is embarrassed just attending. Below is a video of some examples of what NOT to do when presenting (note: these examples aren't real and I've seen far worse). Some of the things to avoid relate directly to technology preso's while others relate to any subject.
And since I'm not a fan of bringing up a problem without a potential solution I'm listing some links regarding how to present effectively. Please list in the comments any additional tips or links that would prove helpful.
How not to present: