When sharing still photos these days I never send them as attachments, I put them up on Flickr (with a choice of private/fruends/family/public), and then Incan send a link to the picture in the email instead.

For videos you can do more or less the same, but using YouTube instead of Flickr. They've also got a "private" option you can use which stops the rest of the world seeing the videos if you don't want them to.

This way there's no worry about cluttering people's disks up without permission (and they can always download the vid if they want - there are free programs out there that enable you to do that with YouTube.) clips.