The clutter of objects we amass is the theme of a tour series that takes in museums, shops and a barmy flat.
Stand beside the skeleton of the Irish Giant. See what the ancient Egyptians threw into their rubbish tips. Squint at a human hair split into a world-record 18 strands. Then sit in a flat whose tenant pretends he lives on the banks of the Nile.

They are all within walking distance (if you have long legs) of the Photographers Gallery in Great Newport Street, near Covent Garden, central London. The gallery has organised Collected: a tour of nine sites - museums, department stores, a shop, and Richard Lowe's barmy flat - most of which have specially mounted exhibitions (until 21 June) of weird and wonderful things to make us reflect, with a smile or a groan, on the bewildering clutter of objects with which we surround ourselves.

Why is it photographers who have organised it? Because it is photographers who are inspired, or hired, to record the clutter that collectors collect and tag and dust down in their never-ending quest to create order.

You soon get the idea at your first stop, the gallery itself. There you see, preserved in photographic prints, an inventory by Christian Boltanski of every object owned by an inhabitant of Oxford in 1974. His toothbrush, his ballpoint pens, his tacky souvenirs, his wardrobe. What a collection. But everybody has one, just as sprawling, just as banal. What will they make of it in 200 years' time? Or even now? Look at his old-fashioned shoes!

You can smirk at Jim Sillavan's obsessive collection of photographs of urinals (snapped when nobody was about, so he never got arrested) without getting bogged down by the Photographers Gallery's pseudo-museological commentary: "We become synonymous with our patterns of accumulation ... we literally collect ourselves into being." Although there is plenty here for the intellectual to ponder, the tour will keep the kids amused, too.

Take the Hunterian Museum, for example. All ages gasp at the skeleton of the Irish Giant, Charles Byrne (1761-83), who stood 7ft 10ins in his socks. As they do at Collected's exhibition there of split-hair art by Alfie West (1901-85): the 18 splices of a single hair that made the Guinness Book of Records are spread in the shape of a lime-tree leaf.

While you marvel at that, you can be sure that the children will have made a bee-line for the collection of reproductive organs that the 18th- century surgeon, John Hunter, preserved in alcohol. Perhaps Damien Hirst should have been invited to exhibit.

Hunter's scientific dissections - here's the point - were as much works of art as West's. His "outsider art" is not the only special exhibit on the tour that gently pokes fun at museum curators' obsession with classification, rather than the objects' appeal as art. A display by the artist-curator Fred Wilson of some of the museum's discarded hand-painted labels - "Wooden coffin of an unnamed woman" - shows how deadening scientific archaeology can be.

But there is a witty double-take in the caseful of Egyptian rubbish juxtaposed with modern rubbish - an installation by the sculptor Richard Wentworth. Is not the craftsmanship of the discarded Egyptian terracotta beer pots infinitely preferable to the garishness of the dented drink cans and plastic cups that Wentworth picked up outside the museum? Ah, but think of the greater intelligence - in design, market research and technology - that went into the modern versions.

At Selfridges you can see British Museum goods - Roman rubber balls, Indian ceramic storage jars - stripped of their context and insidiously inserted into seductive displays of modern merchandise. Can your children tell them apart? Displays in museums and department stores are perhaps not that different, suggests Neil Cummings of the Photographers Gallery. Both "aim to structure our dreams and deepest desires". And both induce you to browse - and browsing, he says, is "a highly creative state".

Browse through the Wallace Collection at Hertford House and you will come face to face with some of your favourite images, such as Hals's The Laughing Cavalier and Fragonard's The Swing - all pink frills and a slipper in the air, lasciviously observed by a beau in the bushes. The swing-pusher, curator-guides relate, was intended by the unknown commissioner of the painting to be a bishop. However, decorum prevailed. Upon inquiry, you will be informed that in 1767 women wore no knickers at all.

Titian's famous Perseus and Andromeda was discovered in Hertford House in 1897, when the collection went public - hanging above a bath. It is still not as steamy a painting as Fragonard's.

Bemused by the follies of collectors and curators, solace yourself in Soho by stepping out of a lift into the deliberate lunacy of Richard Lowe's fifth-floor flat. In 1961, at the age of 16, he toured the Nile with his parents - a formative experience, evidently, as every inch of his living- space is crammed with things Egyptian.

The realistic cracks he painted amid the hieroglyphics on the wall worried architects, who called to inspect the flat. Back in 1961, he walked into several mud huts, each with a couple of dozen trussed-up corpses stacked in corners - ancestors awaiting exodus before the waters of the Aswan dam project engulfed them. There are no such souvenirs in his flat - but he reports that tourists tend to tiptoe round it with almost sepulchral reverence.

There are two more tours of the flat, on Saturdays 7 and 21 June, by arrangement with the Photographers Gallery (0171-831 1772). Other guided tours: Photographers Gallery on Saturday, 7 June, and Selfridges, Thursday 12 June, both by Neil Cummings; the Wallace Collection, Monday, 16 June (the Collection is closed on Saturdays) and a talk by Fred Wilson at the British Museum, Monday, 23 June.