Some people just love to get jokes and funny movies in their email, and then send them around to their friends and colleagues in a never-ending cycle. But PowerPoint presentations and WMVs don't help the Open Media cause, do they?
Still, shouldn't we take the opportunity to promote free formats where possible? Yes. And it's so simple.
If you have people sending you funnies, convert them to free formats and resend. If you have imagination to create your own, then do so. The sky's the limit, they say.
Another thing you can do is to include a link as a sort of email signature to the more popular application that deals with that format. Say, if it's a Theora file you should point people to the Windows codecs, so nobody complains.
Some people will likely complain. "Why didn't you send it in X format? It's more popular," they might say. Don't fall for that. Right now, it may take a bit more work to get Open Media working than, say, WMV, but in time the situation will change. And to get there we need lots of people working with free formats. This is one more thing you can do to help.