Yahoo made a strong competitive move against personal search startups like Eurekster and Rollyo today with the announcement of Yahoo Search Builder, a customizable search engine tool.

A custom search engine can be created that searches just a few defined sites, and/or the entire Yahoo search index and Yahoo News. The search engine can be further tailored to include a specific search term along with whatever the user types in, exclude certain keywords, etc. Once completed, the search engine can be integrated directly into a website via a code snippet.

This is directly competitive with Rollyo (see our posts here) and Eurekster’s Swicki product (see our posts here), which we use for search on TechCrunch – see right sidebar.

Like Eurekster, Yahoo is giving search engine creators the ability to personalize the results page, view search statistics and include a tag cloud of commonly searched terms (this tag cloud greatly increased use of the search engine). Yahoo is saying nothing about sharing advertising revenue with creators – Eurekster is doing this now.