This may be all the reason you need, to consider using open formats like the ODF of OpenOffice.org.
Speaking of different platforms, a big WOW errupted in the room when, at the very end of my presentation, I pointed out that I had started preparing my presentation on StarOffice 9 on my Solaris Sun Ray, then finished it on a Windows Vista using OpenOffice.org 3.1, then took it on a USB stick to the venue and asked the friendly Sun guy, Dave Donmoyer, who was presenting ahead of me to let me present on his Mac using NeoOffice (sorry I forgot which version). I used the odp file with absolutely no glitches. Not once did I convert it to a different file format. I’m telling you, the whole audience was VERY impressed. My last comment was “Try doing that with MSOffice” in a tongue in cheek sort of way.Oh that felt good.