I have found that using PowerPoint is the simplest and most convenient way
to go from a Mac to a PC and visa versa. The 1st 2 quarters of this year I
created over 34 PowerPoints on my PC at home for use on my Mac at school to
show the images that we were studying for AP Art History. Although this did
not represent a small investment of time, the images were better than
slides, considerably more manueverable and were able to be saved
cross-platform (you need to remember to use the .ppt suffix in order for
them to be read both ways). The other nice feature about PowerPoint is that
it also allows you to add text, hyperlinks and additional effects as needed.
I typically use a black background format to make the images stand out more
and use a toned down yellow-ochre color for the text (done in a 20 pt. Times
New Roman font), so that it is less distracting.
Part of the 'manueverability' issue is also the fact that you can give
students hard copies of the PowerPoints that you make (either individually
or by burning many of them together), so that the information is still
available to them during and beyond the class. I found that even if
students don't have Microsoft Office at home (where PowerPoint resides), a
read only copy is available as a download for free from the Microsoft site.