Giving visitors a vote button will shake your faith in the internet. Giving unregistered visitors a text field that doesn't require approval before being listed, that's just downright dangerous! :P
it actually requires approval before it is shown to others ;) making it seem like it was listed when u submit it is a "feel good" thing. of course, if users figure out the quoteid of the specific submission, it is still publicly available. its all in the name of fun :)