Did you catch Malcolm Gluck on TV pronouncing the BYO as the "restaurant of the future"? Bringing your own wine, like they do in Australia, is a nice idea. Unfortunately for those of us who enjoy our wines and food equally, it's an idea to be taken with a large pinch of wishful thinking. I recently took a bottle to one of London's rare, genuine BYOs - the Cook House in Putney. The Cook House is BYO not because it can't afford a licence, but because it aims to encourage eating out without having to pay over the odds. It was as empty as an electoral promise.

Contrast this with Quo Vadis, Marco Pierre White's ultra-fashionable new eatery in Soho. Did someone pay the animal rights protesters demonstrating at the Damien Hirsts inside in order to add street cred? Certainly, nobody seemed deterred by the astronomical quadruple-plus mark-up on the wines. At the trendy Sugar Club in Notting Hill, the short wine list may be pricey and dull, but is it a deterrent? Apparently not.

Here, as in an increasing number of London's new restaurants, business is booming in a frenzy of fin de siecle razzmatazz. Putney Bridge, a new restaurant from the St John stable, has just opened. Four new Conran restaurants are scheduled to be up and running by October. Fancy a table at the Oxo Tower? Leave your name and number on an answering machine. Two evening sittings, inconveniently early or exhaustingly late, have become the norm.

Lauding London's mix of traditional French-inspired and so-called new British cooking, the Wine Spectator, America's biggest-circulation wine magazine, devoted almost its entire February 28 issue to London - "arguably behind only Paris in quality of its restaurants". While 31 of the 54 restaurants reviewed scored 90 points or more out of 100 for either food, service or ambience, only five managed 90-plus for their wine lists (all five are rated expensive or very expensive). "Wine lists should be better than they are," proclaims the Wine Spectator.

Wine lists should be better - and better value. London, as the Wine Spectator points out, is "the crossroads of the world wine market". And wine represents a significant fraction of the bill. According to the Mintel Special Report on British Lifestyles 1997, we drink pounds 2.82 billion of the pounds 5.85 billion annual total spent on wine (and cider) when we eat out. Never mind the quality, feel the margin.

Martin Lam is proprietor-chef of Ransome's Dock, chosen by Wine Spectator as one of London's 10 best restaurants by wine rating. "We need the profit element," he says. "People come to enjoy themselves, and wine is part of the pleasure of their experience." But in Lam's view, 65 per cent (around three times cost price) should be top whack. "Our highest margin is 60 per cent, which tapers to 50 per cent (twice cost price) for our more expensive wines. A lot of restaurants still make 70 per cent gross profit (four times cost price) on house wine, which means they buy rubbish very cheaply and mark up hugely."

Even if it doesn't keep customers away, the problem with the exorbitant mark-up is that it reduces the incentive to choose anything other than house wine or cheaper wines. A more enlightened mark-up policy encourages customers to pick a more interesting wine. In this sense, the welcome trend towards New World wines and more wines by the glass offers greater choice and interest.

In 1995, Decanter magazine, which runs an annual wine-by-the-glass award, declined to make an award on the grounds that the entries weren't up to scratch. In 1996, it received a record number of entries, but too many, it said, "still concentrate on cheap wines by the glass, which misses the point completely". Which is? "To offer wine to customers who may not want to drink a whole bottle but still would like to drink a decent wine."

The 1996 award went to the Pheasant Inn at Keyston, Cambridgeshire, which beat the Nobody Inn in Doddiscombsleigh near Exeter into second place. The Swan in Southwold, the Angel at Hetton in Yorkshire, the Beetle and Wedge in Moulsford, Oxfordshire and the Old Bridge in Huntingdon also have a well-deserved reputation for wines by the glass. Most of these are in the country, although The Avenue and Chez Bruce in London have reasonable selections, the former explicitly offering a generous 175ml glass. Open bottles don't stay fresh for long, however, so the necessary preserving equipment, which is expensive and takes up space, is vital.

The trend towards short, sharp lists in new brasserie/dining room-style restaurants is also fine as long as the style and quality of the wines justifies it. Livebait's list, for instance, is short, and with fresh fish in mind, mouthwateringly to the point. The best are often those where some thought has gone into matching wines with menu and clientele. Gerard Basset, one of Britain's top sommeliers, who runs the innovative Hotel du Vin in Winchester, believes in horses for courses. "The wine list should be flexible and adapted to the establishment. There's no point in putting a three-star Michelin list in a place like Bank" (where he consults).

Since most wine lists are about as easy to decipher as hieroglyphics, it's often hard to know exactly what you're getting unless you're a frequent diner. Restaurants such as Clarke's, Chez Bruce, St John and Kensington Place can be forgiven the stark approach because their lists are not identikit triumphs of form over substance designed with the glitterati in mind. They genuinely reflect the predilections - and idiosyncrasies - of the people running the kitchen. Points of difference are indulged rather than used as an excuse for justifying high prices.

I still like the Ransome's Dock approach. Lam uses a range of suppliers and expends thought into categorising the wines by style and sprinkling the list with useful descriptions. If you have a special bottle you want to drink, the restaurant will charge pounds 5.50 corkage (a few other restaurants will similarly oblige) as long as you enter into the spirit (ie, usually choose a wine off the list as well). But don't do what one recent customer did and bring your own birthday cake without at least ringing first. Lam will charge cakeage - and it doesn't come cheap