There were a few.
George Maciunas of Fluxus has a lovely "Fluxmanifesto" which calls for a democratization of art and the end of the divide between art and life:
“To establish artist’s nonprofessional, nonparasitic, nonelite status in society, he must demonstrate own dispensibility, he must demonstrate self-sufficiency of the audience, he must demonstrate that anything can substitute art and anyone can do it. Therefore, this substitute art-amusement must be simple, amusing, concerned with insignificances, have no commodity or institutional value. It must be unlimited, obtainable by all and eventually produced by all.”
Fluxus in general is inspiring to me.
One of their publications, "An Anthology of Chance Operations" is worth looking at, and available as a pdf here.
Their "performance scores," or instructions for people to carry out thereby creating the art, are interactive in an interesting way. In my mind they relate to SF0, flash-mobs and other contemporary popular art/pranks/games.
Minerva Cuevas operates out of Mexico City, with a solidly social-activist intent for her art. Her Mejor Vida Corp. (Better Life Corporation) will send you cheaper barcode stickers for a grocery chain near you, including San Francisco Safeway.
Locally, False Profit, LLC does what it can to provide "Better living through better corporations." Mostly through providing really, really good music.
Y0UNG-HAE CHANG HEAVY INDUSTRIES is Seoul-based online art. Dakota was most interesting to me of those I looked at.
It seems very post-modern in its narrative, disconnected style. Animated literature is a very good idea and this was effective in that its simple aesthetic was jarring, time-based, and with its use of music created an experience for the viewer.
Rafael Lozano-Hemmer uses physical computing, multimedia, video surveillance and "relational architecture" to make interactive, technology-based art.
I first became aware of his art at the SFMOMA. His "Microphones" piece was my favorite, and relates the most to the work I am experimenting with myself.
Other work I found interesting was his "Relational Architecture" series, including "Pulse Park" which translated participant's pulses into light in Madison Square.
The idea of Relational Architecture is clearly related to Relational Aesthetics, articulated by Nicolas Bourriaud, current curator of contemporary art at the Tate Britain: http://en.wikipedia.org/wiki/Relational_Art