I've been an active developer on the open source project Roundware for the past few months, and it's been very exciting. I've gotten the opportunity to pitch in a project used in Sound Artist Halsey Burgund's last few installations, as well as develop a location-based media platform geared towards ART instead of broadcast. From the page: "Roundware is a flexible, open-source interactive audio platform which can be used to create unique participatory audio experiences. Initially developed for sound art installations, Roundware has been used for museum audio tours as well as other educational purposes. Roundware creates a seamless location-sensitive layer of audio comprised of musical elements and participant commentary in any geographic space. Roundware organizes an ever-growing collection of audio information such that it can be accessed in both educational and artistic ways. Roundware serves individualized audio streams to users in a flexible non-linear way based on participant inputs. So you see, Roundware is the foundation that ANYONE can build an audio installation with. Halsey's video for his piece Scapes illustrates the idea well: Scapes Intro from Halsey Burgund on Vimeo. The exciting news of late is that we're being leveraged by the Smithsonian Institute for their recent Stories from Main Street as well! If you have an iPhone, download it and submit a story - it may end up on the Smithsonian's web page!