In the Jules Verne novel that provides the exhibition Around the World in Eighty Days with its title, the rabbit from a hat is the International Date Line.

When Verne published his epic tale in 1872, this vertical fiction was a new invention: a longitudinal way of expressing the one day's loss that travellers had on circumnavigating the globe from an eastwards direction.

For London's Institute of Contemporary Arts (ICA) and the South London Gallery (SLG), the two institutions hosting this split-site show, the imaginary line that visitors have to cross is latitudinal - the Thames - and slightly more tangible. Is the intersection between these two lines - vertical and horizontal - meant to suggest the cross hairs of a sight-finding device? Perhaps.

Just as Verne's book described a traveller's adventure (and a dare), Around the World is a reflection of modern-day travellers. What do we see in foreign climes? What do we bring back?

At the ICA, Brazilian artists Alexandre da Cunha has lined up eight flags made of beach towels. His Velour Series (the flags hang limply, but one can glimpse snippets of national flags and the insignia of luxury brands such as Ferrari) is explicit: tourism, like fast cars, is a kind of fantasy. A kind of supranational identity for a global culture.

His isn't a new observation, but it's one made with succinct economy, which is echoed, with varying success, by the entire exhibition. Taking a novel as a curatorial excuse for a group show of international artists seems a lazy way of making a travelogue, until one factors in a few things.

Firstly, the world is now much smaller than it was for Verne's Phileas Fogg, and secondly, much of the radical difference that the books described (travelling on elephants, widows self-immolating on funeral pyres) is all but missing in contemporary culture.

As Mona Hatoum's giant floormap of the world (Map 1998) - made out of clear-glass marbles, it is the first thing that greets the ICA's visitor - suggests: homogeneity, rather than heterogeneity, is what dominates.

It's on this last point that Around the World gets good. Across the river at the SLG, the model of a headless man dressed in a suit made of Dutch wax-printed material is balancing wildly (and statically) on a unicycle for Yinka Shonibare's 2005 sculpture.

Shonibare, who has often used this cloth - a material that's popular in central Africa - to restage 'western' events such as Fragonard paintings or moon landings, is astute to the cultural discussions and anxieties around difference.

One feels that it's Shonibare - a British artist of Nigerian heritage - who really goes to the heart of this travelogue of a show, and is an artist whose work is a playful stab at what can be most fraught.

Louise Gray is a freelance arts journalist

Around the World in Eighty Days, ICA and SLG, until 16 July 2006.

Information: www.ica.org.uk and www.southlondongallery.org