Then they make the most unexpected proposal: if you let them into your home, they will cook you dinner.

What would you do? Would you slam the door in their faces, suspicious of their bizarre proposition? Would you make some lame excuse and get rid of them? Or would you take a chance, let them in, and see what happens?

This was the dilemma faced by many Limerick households recently when two artists, Jennifer Nelson and Dimitri Kotsaras, went door-to-door around the city, offering to do just this. It was one of many events that have been taking place in Limerick as part of the annual contemporary art exhibition, ev+a.

Now in its 30th year, the large-scale, city-wide exhibition, which is on show in various galleries, institutions and offsite locations, is distinguished by the fact that each year an international curator is invited to take the helm. This means that ev+a has no fixed format, and is refreshingly different every year.

This time round, the honour has gone to Greek curator Katerina Gregos. She selected some 70 Irish and international artists, both invited and through open submission, and decided to have a themed exhibition. She chose the title of 'give(a)way', with the focus ?on generosity, giving, sharing and social exchange".

There is a risk with themed exhibitions that the art is considered only in relation to the overarching theme rather than for its independent merits. And when, as with this year's exhibition, many of the artists are specially commissioned to create new work, there is a possibility that they feel pressurised to create something that 'fits in' with the theme.

There is certainly a specific aesthetic to this year's ev+a: the theme of generosity suits art that is process-based and interactive, along the lines of Nelson and Kotsaras's 'cooking experiment'. ?Ev+a 2006f hopes to adopt a community-oriented and civic-minded approach and, by extent, a stance which is critical of today's neo-liberalist culture which puts self-interest and capital gains above human consciousness, " says Gregos, who wanted the exhibition to engage directly with the people and the city of Limerick.

This she has certainly achieved, but with varying degrees of success. One of the problems with work that exists through participation is that the end result can be disappointing. Neva Elliott, for example, has invited people to log an act of generosity on a website (www. nevaelliott. com/respond).

However, only a meagre 14 people have contributed since 12 March. Another disappointment is Ursula Kelly and Maeve McElligott's one-dimensional Post-it project, in which passers-by in Limerick were invited to write what generosity means to them on a Post-it. It was, perhaps, too literal an interpretation of the exhibition's theme.

A much more successful participatory work is Nina Tanis's moving and absorbing installation in the atmospheric St Mary's cathedral, where hanging on strings are translucent pieces of paper on which visitors have written about a moment of happiness.

You can add one yourself, and you can listen to a simple but profound story on a portable CD player.

Storytelling also figured in Johanna Lecklin's 'Story Cafe', in which Limerick locals were invited to tell a story in exchange for a coffee. Mario Rizzi's multi-screen installation, 'nextdoor', focuses on personal stories told by marginalised Limerick individuals. The storytelling strand is also evident in the emphasis on songs as a means of expression, from Juan Manuel Echavarria's video compilation of singers telling tales of war-torn Colombia, to Yvonne Buchheim's 'Song Archive', to Tellervo Kalleinen and Oliver Kochta-Kalleinen's 'Complaints Choir', which involves a humorous song about such everyday frustrations as slow computers and infrequent buses.

Other projects have a limited timescale or are ongoing. For Enso's 'New Treaty of Limerick', people were invited to reflect on the state of the city and make proposals for improvements, while Seamus Nolan placed an ad in local papers offering a rent-free space in the Granary for the duration of the exhibition.

And then there is Superflex's 'FREE BEER' project. It does exactly what it says on the tin: the artists' group have taken out a creative commons licence which allows anyone to use their recipe and brand to brew, market and sell their beer. Now that's worth drinking to.