Twitter have announced that they have acquired Summize, which is a search tool that looks through Twitters database of users and brings back relevant search results. This means that they have moved the service to their own website at See below for the official press release:

We’re excited to announce that Twitter has acquired Summize—an extraordinary search tool and an amazing group of engineers. All five Summize engineers will move to San Francisco, CA and take jobs at Twitter, Inc. This is an important step forward in the evolution of Twitter as a service and as a company.” Read more here.