Last night at free103point9's Noise! festival at the Ontological Theater in Manhattan, Jeremy Slater and Tamara Yadao used the FMjam transmitter in his performance. It is a small transmitter with numerous effects on it, marketed to guitar players and such who want to jam together. Slater and Yadao both played with one, and the FMjam allowed them to both perform on the same radio frequency. Apparently, up to five people can "jam" together on the same frequency with this transmitter.