Inherit areas of parent or ancestor page I have a website built with Drupal 7. Each page on the site can have an infinite number of child pages. Each page has "areas"; an area can be a thing such as left or right side bars that contain blocks, views or attributes/fields of the page content type (e.g., page.sponsor_ad_1, page.sponsor_ad_2).

I want the child pages inherit the areas of its closest ancestor page by default. A content editor can override it afterwards.  

What's the best way to achieve this? What module does, completely or partially, what I need?
It depends how arbitrarily flexible the layouts need to be but:

For the layout switching you could probably use Omega and Delta http://drupal.org/project/delta

Then write your own custom context condition that says "does this page have a parent with the layout X?" then use the reactions provided by Delta to switch to layout X for the closest parent.

For the defining/storing what layout is associated with each "page" you could just use the Field API. If each "page" is a node then it will be easier for you, otherwise you might have to also define a new type of Entity for your site.