Limit number of pages opened in seconds?

[Dave]

That's not possible unfortunately, it's how the world wide web works. Even if it was possible with the use of cookies, IP checks, flash cookies, etc. it's still easy to bypass.

You can however throttle the amount of requests that are sent to the server within a certain amount of time. (More of a DoS protection feature) This can be done in the configuration file of your web-server. You should probably ask your host to do that though. Just keep in mind that this way is far from perfect and I would just leave it as it is.