First revealed by All Things D in April, The Wall Street Journal reports today that some users of Twitters mobile apps are seeing a new Nearby timeline that surfaces local tweets. Twitter has never excelled at local discovery — location is turned off by default for tweets that users post from their phones — but the fact that the company is moving forward with testing suggests that it still has its eyes on the prize. Twitter declined to comment to WSJ on specifics, but gave its usual refrain that its always testing features through its Twitter Experiments program.