I first created this presentation for the Drupal Camp 2011 in Kiev, but I have given it at a few other locations and conferences, such as LOADays 2012.
Since it is a talk about Git, the talk itself obviously is also version controlled with Git. Since I'm finally really tired with WYSIWYG presentation software (yes, even LibreOffice Impress), I tried something different. The slide show is written as a single markdown document, which is then converted using the nice S9 application. It uses the 'HTML5 Google rocks' template to give it a very cool and clean look.
You can see the rendered presentation here: https://budts.be/static/media/talks/git/version-control-with-git.html5.html#slide1
Maybe you can watch the slides below as well, but that depends on CSS3 support in your browser, so it might not work...