Windows Vista – Office 2007 compatibility with ms office 2003

Hello,
I have Vista and the office 2007 on a gateway computer. I create documents, such as, power point presentations that are not compatible with the ms office 2003 version. If I email a client a presentation they can not view it. Is there any changes for that. I know there is a converter out there, but doesnt the one that has ms office 2003 need to down load that before they can view my email. Which means if they are a business they need to get with thier IT to be able to down load any software. Is there a solution here? thank you
Errin