Twitter is poised to launch a photo-sharing service, a move that could make popular third-party applications such as TwitPic and Yfrog obsolete, sources say. The move is unlikely to prove popular with developers, who already resent Twitter's willingness to launch features that duplicate their services, but could provide users with a more streamlined and feature-rich basic service, observers say. "Twitter users like to type status updates, but they also like to share photos. ... [I]t makes perfect sense for Twitter to do what it needs to do to improve that experience," E.B. Boyd writes.