British mobile-application whiz Nick D'Aloisio continues to develop his Summly news-summarizing app, which has been downloaded a half-million times in about four weeks. The 17-year-old wants to expand the program to the Android platform and larger screen sizes, and is arranging deals with publishers to allow the app to peek behind pay walls. "It's pretty clear there's a massive opportunity with what we're trying to do with information overload and [natural language processing] and all these different areas taking off right now, and we're at the center of it," he says.