I was just at Fear Factor LIVE a week ago and - considering the entire thing is professionally filmed - it doesn't make sense why that wouldn't be an option (at least for the people participating. We actually talked a little bit about this subject on the Universal NOW podcast. With iPhone and mobile phones getting much better at taking pictures (and being small enough to carry with you everywhere), the need the for paying for pictures is shrinking for many guests. However, no matter how many pictures we can take, I don't think any of us can get high quality vide of attractions. Currently there is a limited use of this feature on Rip Ride Rockit, but I think there is a major opportunity to do exactly what the OP wants.
Not only could you use this for Fear Factor LIVE, but Animal Actors on Stage has a lot of interaction as well. It would also allow people who do have friends and family there to be able to experience the "memory" instead of having to take a whole bunch of photos/video. We're already in an era where a DVD-R could be made within minutes of the show, but you could even just have these available for download and "sell" the link via email.