as PPT

Please compress images before delivery. Most of the presentations I got in the last time had images included that were huge but resized to a fraction (see usage of images). But even if the visible result was tiny the file size was not. Thus, my recommendation is to use the "compress images" option before publishing to decrease file size.

Another important point if you do not want to embarrass yourself is to delete inappropriate comments before giving everyone else a copy of your file.

Many people seem to forget that there exist more than one program to create presentations. Nowadays we can use traditional local installed software (e.g. Powerpoint, Keynote, LibreOffice,...) or use online offers (e.g. GoogleDocs, ZohoShow, sliderocket,...). Some of the latter are also trying to invent new ways of presentation (e.g. Prezi). Most of these tools are using their own proprietary file format. So you can be pretty sure that - as long as you do not use the same software company-wide and only giving the presentation to a collegue - not everyone will be able to see the presentation in the same way as you intended.

In addition to that, even if everyone uses - lets say MS Office - there will be still problems. One misterious thing I have seen so far is that when you do a presentation (pptx) in Office2007 (win) and open it in Office2008 (mac) most of the items are on a different position (and vice versa). It appears that both programs start their measuring from different starting points. Thus, when you prepare a presentation on one operating system but have to present on the other this might end up in a big mess. Those cases are often in university and conferences where you have to hand in presentations up-front and (at least in uni) they are opened the first time on the "presenter pc" as soon as you step on the stage - but then it is too late...

Another example for problems when using different tools when opening a presentation is the interpretation of theme information as shown in the following image:

Also some images (especially cliparts) might not shown correctly or at the intended position:

better: From my point of view it is nearly always better to publish the final presentation as a PDF file.