Google's has a sort of new Custom Search Engine service. As I read about it, my link building antenna started chirping....


Why? Because I'm a content publicist, and in my field vertical engines = new link and publicity opportunities. There are many vertical engines as well as tools to create them. Rollyo is one well-known one, and now Google is getting serious about it as well.
What does it mean for link-builders?
You need to make sure you identify any and all high-quality vertical engines that fit your content. Then, request inclusion by the vertical engine's editors. This may be easy as submitting via form on the individual engine's site, or could require serious lobbying and begging, since by their very nature vertical engines tend to be picky.
It will always boil down to content. You have to have the type and quality of content that adds value to the engine's results, or why would the engine's editors want to include your site in the first place?
Here's two sites operating Custom Google Searches:
Food and Agriculture - Search for information about food and agriculture recommended by the Food and Agriculture organization of the United Nations. (Pssst. Hey Kraft! You in there yet? How about you, Dole?)
RealClimate is a consortium of scientists who comment on articles related to climate change and global warming, to help non-scientists better understand the complex issues regarding this subject.
These are just a couple examples. There will be more. Trust me. So get your antenna up and look for the engines that fit your content on a regular basis.
BONUS TIP: TrackEngine this page. I did.
Links for more information: Google Custom Search Engine
Featured Google examples: http://google.com/coop/cse/examples/
Link well, my friend,
Eric Ward - http://www.ericward.com