Tom Sutcliffe: Are you talking to me?

It's slightly odd, when you think about it, that we expect to be ignored in the theatre. We're the reason the damn thing is happening, after all, and yet in 99 cases out of 100, everyone involved pretends we're invisible. The curtain rises and the people on stage start talking to each other, or occasionally themselves, as if we're not there. And worse... if you make it too obvious that you are there, by taking an urgent phone call, say, they get absolutely bloody furious. "Who's paying the bills, pal?" you might be inclined to ask – but of course you never do, because our invisibility and our muteness is part of the contract.

It can't always have been that way, surely? It's not the obvious place to start, however familiar and fixed a convention it is now. You go to all this trouble to assemble an audience, to lure them into place – and then you pretend they're not there at all. It's the kind of perverse variation that you invent when missionary-position theatre starts feeling a little old.

These days, of course, being ignored is vanilla sex, theatrically speaking. And, when the opposite happens – as it has on a couple of occasions in the theatre recently – you feel a frisson of revived interest. On the London stage now both John Guare's Six Degrees of Separation and Douglas Carter Beane's The Little Dog Laughed make a lot of use of direct address to the audience, and the way that they do it is revealing about the odd cross-currents of feeling it can set up in a theatre.

In Six Degrees the matter is fairly straightforward. We're recognised as an audience of a different kind, the recipients of a long and delicious anecdote about a couple's subjection to a charismatic conman. It's one of those stories that would monopolise a dinner party, and the fact that the actors speak directly out at us barely disrupts the "fourth wall". There's never a moment, as far as I can remember, when there's any sense of "theatrical aside". They aren't saying one thing to us and another to other characters on stage.

The Little Dog Laughed is a much less interesting play but involves a far more interesting deployment of the device. Everybody's at it here – buttonholing us like crazy. But Tamsin Greig, who plays a cynical theatrical agent, takes the direct address one step further. The other characters want our belief. She simply wants our attention and the way her role is written places her in a position suspended somewhere between the stage and the stalls.

When the second half begins, for instance, we find her in the middle of a phone conversation with one of the characters and she gives us one of those "This is boring, I'll be with you soon" looks. We are, in other words, the people who are really present and who truly know what's going on.

And that feeling is sustained even when she turns to flick us a meaningful glance in mid-scene. Generally speaking our model for such moments is the soliloquy, but there is a real difference here in that Greig's character knows we exist and – more to the point – she knows that we know she doesn't. The performance hovers deliciously somewhere between a cabaret act and characterisation, and her acknowledgement of all that makes us feel that her speech is somehow truer than all the speeches that frame it. Clumsy directors sometimes make the mistake of thinking that's what soliloquies are about on stage; that by looking us directly in the eyes the characters will establish the sincerity of their utterances. What they forget is that soliloquies – as the name insists – are actually about not being overheard by anybody .

Tamsin Greig's character doesn't soliloquize, she conspires. For once the people we're all pretending aren't there while she talks are the ones behind her on stage.

Pay and display

As Apple nudges us closer to a world in which physical books are collector's curios it may be worth pointing out that the internet could still offer renewed life to a very old model of publishing – the subscription edition. The US blogger Andrew Sullivan explored this recently, bringing down the cover price of a collection of readers' photographs of the views from their windows (it's a regular feature on his blog) by soliciting promises of intent to buy in advance of publication. And not long ago, as one of those who'd signed up for the One and Other project by Antony Gormley (below), I got an email offering a pre-publication deal on the 700- page book being published to document the event. The cost of canvassing for buyers, in both cases, was absolutely minimal – and the resulting print-runs, I would have thought, much larger than if the traditional "guess and pulp the leftovers" process had been followed. What I'd like to see now is the write-on-demand book, some shrewd author issuing a seductive prospectus for a novel or a non-fiction work and only pressing ahead when enough readers had signed up to cover the costs. I know Stephen King had a crack at this years ago (and the idea failed) but surely the time and the technology are now ripe for a method that made writers as different as Alexander Pope and Mark Twain a substantial amount of money. And given the availability of print-ond-demand services you wouldn't need to involve a publisher, provided the name above the title was big enough.

* I was sorry to read that the Institute of Contemporary Arts is in financial trouble – that subterranean warren off the Mall figuring fairly significantly on my own cultural map of London. Thinking about it though, I realised that I haven't been there a lot recently. This could mean one of two things I suppose – that I'm getting too old for the kind of radical fringe that the ICA used to represent, or that the radical fringe is available pretty much everywhere else these days.

I would never knowingly underestimate my own fuddy-duddyness in this matter, but the latter explanation must play a part in this too surely? If you can visit Tate Modern and encounter pornographic video art or go to the London Coliseum and watch La Fura Dels Baus doing Le Grand Macabre it's quite hard for the ICA to carve out a space for itself as radically alternative. And since the internet has proved so good at providing a meeting place for the fringe of the fringe, that's also eroded the Institution's raison d'etre. What it needs to make it work is a community of people who feel excluded from received opinion, and who cherish the idea that this is a laboratory of aesthetic resistance. It needs a cause – in a world where its own original cause has largely become the norm. There is a solution which wouldn't even require a change of stationery, though I fear that the current staff might not care for it. It should become the Institute of Conservative Art.