The skateboard joins the canon of everyday objects that have gained art- object cachet - a process begun by Marcel Duchamp exhibiting a urinal in 1917. But this is not a return to the old "ready-made" project in which everything can be art provided it's on show: embedded in Felix's skateboard was a compelling paradox. "Camouflage was devised to be invisible in foliage," says Wentworth. "But now, reduced to ornament, it is meant to be seen against a concrete background." This innocuous youth-cultural emblem passed on a visual secret about the "way we relate to nature".
Such riddles of everyday things are gifts to Wentworth, best known as one of a generation of sculptors, based around London's Lisson Gallery, who came to prominence in the early Eighties. Thinking Aloud is an accumulation of objects: some made by artists, others unearthed from various obscure sources.
There is a Durex mould made of glass; preliminary sketches for Joseph Paxton's Crystal Palace; a blotting-paper doodle by Lloyd George; a body bag; patents for Nike shoes; early Tube maps; and a model by the architect Frank Gehry. Then there is a graphic illustration of the various Shipping Forecast zones, familiar from BBC radio. "It's a standing joke in the country, but it's something we've never seen," says Wentworth.
In the second and third legs of the show - at Manchester's Cornerhouse and London's Camden Arts Centre - there is to be an Independent front page, without words or pictures. Artworks have been contributed by Rachel Whiteread, Patrick Caulfield and Tim Head among others, but all exhibits are treated even handedly.
This approach is eclectic, fun, a spur to the imagination, but the bagginess of the show's theme may irritate. Wentworth hopes people will get a version of the "Eureka" syndrome - "That idea of seeing greater meaning in the bathtub," he says.
Given that Wentworth possesses an air of professorial butterfly-mindedness, it is tempting to see this as a modern version of the exhibitions of the great boffin collectors of the 18th and 19th centuries: the Levers, Pitt Riverses and Soaneses, who sought out wonders and curiosities.
But a poke around reveals a theme-in-progress that is less about mere display, more an examination of the nature of creativity. It was to have been called First Thoughts, and several of the exhibits are of sketches and models - Wentworth calls them "conceptualisations", with a wince - leading towards the conclusions that life is an unresolved process; and human resourcefulness and political resonances are found everywhere. Prosthetic hands show how artificial limb technology has developed and how Army officers got fingers and thumbs, while labourers made do with a hook.
The lender, Charing Cross Hospital, feared they were to be shown for "ghoulish" effect, but Wentworth says he was completely against surrealist nightmare imagery. "It's to put back into the mind what incredible things hands are." He's emphatic the show is not an old curiosity shop, soggy with sentimental values.
There is an eccentric zeal to Thinking Aloud. "I did think: `Oh my God, it's a boy's show'," says Wentworth, holding wooden sticks of mock dynamite found by the artist Cornelia Parker. "But I realised that there were lots of women artists in the show. In fact, Cornelia's the only one who has actually blown anything up." (Parker exploded a shed, as seen in last year's Turner Prize exhibition.) Visitors can make their own, more gentle mark, such as words on a Scrabble board. This is the show's elusive but illuminating spirit: to show the human need to make order out of chaos and, as Wentworth says, "to come back to the idea that everyone is an artist".
`Thinking Aloud', Kettle's Yard, Cambridge (01233 352124, to 3 Jan); Cornerhouse, Manchester (from 9 Jan), and Camden Arts Centre, London (9 Apr). A national touring exhibition from the Hayward Gallery