Using prezy and other slideshow tools

Prezy Prezy is a new tool which allows you to create more complex slide presentations than other software, and it allows you to collaborate with other people. I think that it can be a very useful tool. However, if we do not use it carefully it can be both helpful or harmful. Why? You might ask. Well, the following tips apply to most slideshow software:
-Do not put a lot of text together. Our mind can manage 7 +-2 elements at the time, so try not to use more than 7 lines and 7 words per line.
-Do not use pictures that do not provide any relevant information, as you are focusing attention somewhere else. As an example, in one of the recent presentations we had, most slides were full of pictures, gif's etc. which were as funny as irrelevant (even two ladybirds having sex on top of a road sign). Use images that provide information related to the matter (sometimes they give you much more than several slides of text) or, within a reading promotion context, use images that work as scaffolding, providing information that your pupils might not be receiving through verbal communication (and therefore helping them to understand).
-Try to use black letters over white background. I know it doesn't look cool, but it makes it accessible to everyone. If you are using a rainbow of colours, be ready to adapt it whenever is necessary.
-When using Prezy, try not to do sudden camera moves. It distracts people and makes the whole thing more difficult to follow. Some people have even reported cases of people feeling dizzy after watching a slideshow with this characteristics.
-Download a PDF version. Not everybody uses Microsoft software, and your internet connexion might fail. If you download a PDF version you will be sure you will have your resources available. As an example I'm going to show you two different presentations. The one that is in English is, in my opinion, the best (although I'm not entirely happy either) as the way the camera moves between rings helps to understand the relations between them (although like I say it has to be improved). The second one pretends to look somehow like a river that flows (it is a presentation about the quality of Burgo's main river water), but that makes the camera move constantly from one place to another.