That implies they don't see the value in owning such a device, which means they aren't likely to see the value in having one given to them.

I wouldn't rule it out if that's what someone wants, but I would stick with DVDs as the default. Especially since you can custom-label/print the DVD surface with an image from the wedding. The non-tech people just eat that stuff up.

Also because this isn't likely to earn you the business in the first place. But it may be something to advertise as an option. "Digital negatives delivered on DVD or optionally a USB thumb drive"

Or you could give away an iPhone with all the images stuffed onto its camera roll and the default number in the phone book programmed to your office so they can order more prints. Of course they can just click on the image in the photo viewer and shoot you an email which will be faster - and can possibly be automated on the mail server... Now that's interesting.