如何防止在rails应用程序中过快地重新提交表单？

I have made a simple Rails application that allows people to comment on posts. How do I prevent that user from submitting that form over and over again? On reddit.com they only allow newer users to make new posts every ten minutes. How can I do this with my simple blog/commenting system? Any help would be greatly appreciated. Thanks for reading my question. EDIT: I'm trying to accomplish this without a user model.I have made a simple Rails application that all