Pasadena-based Perfect Market Technologies, operator of the Snap.com web search engine, said today that the company has rolled out a new visual search service. The new service shows preview images of web sites as part of web searches, similar to the firm's recently released web site preview features. The new web search capability shows a preview of web sites found in the search results, allowing users to decide if they'd like to visit a site. Perfect Market's preview service allows bloggers and other web site owners to show visual previews of web sites when users hover over hyperlinks. The firm backed by Idealab and Mayfield Fund.