Gazopa, a search engine that uses features from an image to retrieve similar images, has been in private beta since it launched during TechCrunch50 last year. To recap, Gazopa lets users upload a picture, enter a URL of an image, create a drawing or right-click on an image anywhere on the web (via a plug-in) and retrieves similar images. A thumbnail of a video is enough to look for similar videos. Results are mainly filtered through analyzing the color and shape of the object or person pictured. Upload a picture of a red car, for example, and Gazopa will find pictures of similar cars on the web - without you having to type any keywords (search via keywords is also possible though).Since September 2008, more than 40,000 users have tested the service, which entered open beta today. And Hitachi America, the company behind Gazopa, has used customer feedback to improve the quality of search results, tweak the site's design and add a number of features in the past year.