Or call them the Fab Six. They were -- beginning with the youngest, who was 24 when the group was founded in 1961 -- David Greene, Michael Webb, Peter Cook, Dennis Compton, Ron Herron and -- 10 years older than Greene -- Warren Chalk. They took their name from a publication they occasionally produced, Architectural Telegram.

The archetypal modernist Le Corbusier would die in 1965, but it would be an exaggeration to say that Archigram killed him. Even so, the group was thoroughly irreverent towards "the decaying Bauhaus image" and all the rest of the modern canon.

In its place they all envisioned -- and drew with appropriate showmanship -- a spirited new amalgam of technology and organic forms. Plug-in cities, blow-out villages, wearable houses (called "suitabloons"), air bridges, soft shelters, idea circuses, seaside bubbles, robots, capsules and pods. Most striking of all, perhaps, were the walking cities, giant inhabited mega-structures striding through the landscape on telescoping legs.

It all remained resolutely unbuilt and unbuildable. That hardly mattered. It was meant to be provocative, and it was. Influential, too. The celebrated Centre Pompidou in Paris, designed by Renzo Piano and Richard Rogers in 1977, was a direct descendent. Archigram revisited today, over 35 years after it first flourished, with the group disbanded and only four of the six founders alive, still presents an air of optimism, excitement, energy and iconoclasm.

The San Francisco exhibition is in two locations. At the San Francisco Art Institute's Walter/McBean Gallery are installation pieces from the Archigram archives plus a work by David Greene dating from 1968, a naturalistic mound with electronic infrastructure, something like a compost heap into which you can plug a computer.

At the San Francisco Museum of Modern Art are more than 200 drawings, collages, models and videos. The SFAI show is up till May 2; the SFMOMA exhibition through June 15. Both were organized by Thread Waxing Space and Pratt Institute in New York and SFMOMA architecture curator Aaron Betsky in San Francisco. Funders include the J.M. Kaplan Fund and the Graham Foundation. Pow!