It's the influence that counts. The Pompidou Centre in Paris by Richard Rogers and Renzo Piano, for instance, could not have sprouted without the rich early 1960s fertilizer of radical alternative ideas blended by Archigram and Price. Over in Czechoslovakia Jan Kaplicky, later to come to England and set up Future Systems, lapped up both the style and the message. His bulbous polka-dot Birmingham Selfridges is a frozen Archigram vision of an unthreatening spage-age future. Will Alsop's colourful blobby architecture, so much in demand, derives from the same source. The group itself became unfashionable as its optimistic belief in the redeeming power of technology came to appear naïve in the late 1970s and early 1980s, but today, in a wireless world of mobile communications and cheap mass transport and advanced building techniques, these old men seem like prophets.

As always in architecture, it helps to live long, stay the course. Archigram may have lost Chalk and Herron along the way, but the others are now starting to reap the benefit of their early investment in blue-sky thinking. Cook and a later member of the group, Colin Fournier, have finally built something. Calling themselves Spacelab, they are responsible for the spiky blue-plastic blob of the Kunsthaus in Graz, Austria, with its electronically-illuminated chameleon skin. So a historic centre now has a most uncommon art museum. It cannot get up and heave itself from place to place as Archigram once imagined - it is a rooted building - but with its pulsing skin it can change its appearance, seem to be ephemeral.

Cook and Fournier call the Kunsthaus a "friendly alien", and that is really the whole Archigram project in two words. It's alien, but it's all right. It's friendly. We come in peace. Spacelab continues the spirit of Archigram, and they have finally got to tune up a city. So what that it has taken over 40 years to get to this point? 40 years well spent, I'd say.

www.designmuseum.org - were Archigram the Beatles of architecture?
www.kunsthausgraz.at - see where Archigram ended up.