When creating a page, it should be possible to password protect that very page.
To extend the feature, it should be possible to password protect a whole area on a website. For example, anything under the /protected/ path would ask users for a password before they can access the data.
This mechanism has been used for photo galleries where a set of photos is uploaded online and the photographer gives the customer access to that section of his website. With this property in the core system we can easily make this work.
Also this is great for Internet Marketers who want to lure people in their website in order to get them to move forward with a purchase (i.e. the /secret/ path!)
It should be possible to define passwords that only unlock one page (specific), some that unlock an area (per type), one that unlocks all protected nodes (global).