The winners are announced of the 2010 edition of the Slideshare World's Best Presentation Contest. Here are the #1, #2, and #3. Congratulations to each designer:
Some lessons we can learn from these presentations:

• Dare to use fonts beyond the standard ones (but make sure that it does not create problems)
• Select images with lots of white space
• Match image style, image color, font, font color on the same page
• Maintain a consistent graphical styles across slides
• Look at the people-flat-on-the-ground sequence in the smoke presentation to see how you can achieve cinematic effects in PowerPoint