Suggestion: Delete this thread and drop the idea. It's useless and only makes bitcointalk look even more like a joke. It was bad enough to snap the ripplelab-domains and start trying to sell them.

Want a little more info about my suggestion?
... Sure but first tell me how you would distribute the stamps used to make spamming the network harder/expensive. Actually there's one alternative way - that is to give people these stamps depending on their bitcoin stashes - but that's not very good after all.