France's contribution to the unisex debate - the Superloo

The block, which is home to a number of young companies, does away with the convention of separate "ladies" and "gents" loos by combining the two.

Reaction from the workers has been positive. "It's a great leveller," says Nick Hayward of Nexus, the office service provider whose buildings contain the toilets.

Television fans will link the idea with Ally McBeal - the quirky comedy set around a trendy Boston law firm where the "communal bathroom" is a centrepiece for trading office gossip.

But in real world America businesses have been switching to unisex toilets, often in the name of equality.

Unisex etiquette

Men should remember: not to expect a urinal - cubicles only to put down the loo seat to always wash their hands Women should remember: not to hog the mirrors to leave some loo paper for the men not to take too long

They are getting to be commonplace in restaurants, bars, halls of residence and shopping centres. The Tunnel nightclub in New York even boasts a unisex restroom with a full-service bar.

And the gender blending has been catching on this side of the Atlantic. Mixed loos can be found in bars such as Belfast's BT1, Garlands in Liverpool and Edinburgh's Bar 38.

It may sound like a gimmick, but advocates point out they do away with the common disparity of long queues outside the ladies but not the gents.

Of course, unisex toilets or "co-ed bathrooms" as they are called in the US, are really nothing new. Everyone has them at home and disabled people are well used to sharing their facilities in public places.

But not everyone is comfortable with this shift in social attitudes. In America, Bob Glaser sued after women, tired of queuing, invaded the gents toilet during a San Diego rock concert.

Everyone is used to mixed bathroom facilities

Mr Glaser said his civil rights and rights to privacy had been violated and he was unable to relieve himself in front of the women. The experience left him "angered, upset, embarrassed and distraught".

That the case was eventually thrown out of court for being "frivolous" is testament, perhaps, to how little physical segregation exists between men and women.

So what could be next in line for the communal treatment?

Men's clubs - According to reports in the press at the end of last year, male-only clubs such as the Carlton and Garrick, both in London, are living on borrowed time.

There was speculation that single sex clubs would be forced to go mixed under new provisions in the Equal Opportunities Bill. The same rule might be applied to golf clubs, about 70% of which ban women from particular bars or deny them access on certain days.

Women are common in the military

Changing rooms - For some swimmers and fitness enthusiasts, the mixed changing room is already here. Also known as "changing villages", the idea comes from Germany, where mixed saunas are common.

Harrogate Hydro is one leisure centre leading the way in this field, although initial reaction from paying customers was less than enthusiastic.

Armed forces - Although women are commonly accepted into in the British armed forces, some exclusions remain. They do not sail on Royal Navy submarines and are banned from hand- to-hand fighting.

Hospital wards - NHS efficiency savings mean mixed-sex wards are a reality in many hospitals. But the tide has been turning and it was a Labour election pledge in 1997 to abolish mixed wards.