Eurekster got into social search before everyone else but didn't really have success with consumers, who might have been confused by what the company was trying to do. Eurekster has had B2B success with publishers, however. Along those same lines, the company has now launched swickis, which is a search box for small publisher sites and blogs.
Publishers and bloggers can set up swickis on their sites for free. They first answer questions regarding the content of their sites, which then become a kind of contextual filter for search results. Readers can then use the search boxes to conduct related searches (tags appear identifying popular searches), which are customized to the site's content (and presumably the site community's interests).
Here's an example of how it appears, on the Eurekster blog itself (also read the posts to gain insight into the company's thinking and rationale for the product).
A contextual ad network is being built on top of this. Unlike the original consumer engine, this product probably has some "legs."