Keyword search gets you pretty far when looking for pure information, but doesn’t help much on more qualitative searches like trying to find the hippest restaurant in SOHO. Searches like the latter rely on the opinions of people, not webmasters, which is one of the reasons Circo’s has launched their new qualitative search engine. The engine currently lets users search for hotels and restaurants by qualities like size, ambiance, or other qualities pulled from reviews from around the web. They have plans to expand to other categories in the future.

Circos is categorized under the ever expanding umbrella of semantic search engines, which currently includes the likes of Hakia, PowerSet, Kosmix, SemantiNet, Quintura, and TrueKnowledge. However, the engine is most like Kango, which has also taken on the task of categorizing hotels based on user reviews. VibeAgent also has a search engine for its own site that will search hotels based on qualities.

While Kango auto-generates tags after pouring through user reviews, Circo lets users search for any qualities they’re interested in. The engine then grades and ranks the results by each quality on an “A” through “F” scale based on how well the description fits for reviewers. For example, a hotel reviewers feel is spacious would rate highly if searching for openness, but poorly if you’re looking for a tiny room.

As with most search engines, Circos’ real test will be whether its application draws users away from other hotel and restaurant sites with less sophisticated search engines. Currently there are a bunch competing in the space. However, Circos says their technology can easily be extended to other categories since their algorithm does all the tough work of pulling the most relevant qualities from reviews. If hotels and restaurants don’t appeal, another category may hold their home run.

Circos is angel funded, based in San Mateo, and has eight employees (4 in Singapore).