Google AdWords offers Section Targeting

Great deal for advertisers. Some content sites are fairly mixed, with a limited number of pages being relevant for a particular product or business model.

Site targeting places your ads on individual sites in the Google content network. Site sections take that one step further by placing your ads on only one section or even one page of a site. If you sell soccer shoes, for instance, you might choose to advertise only on the sports section of a news site rather than placing ads across the entire site.

Select a site section by entering its URL in the AdWords site tool or in the 'Edit Sites and CPM' section of your account. If the full site is example.com, the section URL will take the form example.com/section. You may target individual pages by using the form example.com/section/page. Refer to the URL of the actual site to see how its sections are named. Source

If a site ranks where you want to be seen you can target ads at that specific page. Absolutely wonderful for marketing a product against an old competing one.

A while ago I also mentioned that if these page targeted ads were far underpriced some webmasters may be inclined to spam for authority sites to get the ads they place on them a bit more exposure. The ad market really is opening up :)

A great SEO tool that needs to be made is one that searches the search engines for desirable keyword terms and returns the result pages which offer AdSense ads on them.

I would imagine it also would not be hard to automate adding those pages to an AdWords account, and automate building a bit of link popularity for them.