Cityspeak is ephemeral graffiti, an exploration into the use of private modes of communication to drive transient public displays of commentary about a particular location. Participants use their SMS- and web-enabled cellphones or wireless PDAs to send text to a common server. The text is combined with real-time data from the location and processed using the NextText text visualization software. The resulting stream of text is layered back onto the locations in the form of large-scale projections. Participants can use the display to leave commentary, tell stories, conduct conversations or simply to play with the visual characteristics of text.

Cityspeak is an example p2P (private-to-public) communication which allows participants to use communication technologies we tend to think of as private--cell phones and personal digital assistants--to create public displays. p2P projects examine how culture of the street can interact with the commercial culture of media saturation.