First came SatNav, the satellite system that helps guide even the most hapless drivers home – now the "SatLav" has been unveiled, to guide shoppers to the nearest toilet.
The new system uses satellite technology to pinpoint the whereabouts of the anxious user and then sends them details about their nearest convenience.
It is one of a growing number of services available to mobile phone users, who can already use their handsets to get directions or find taxis, plumbers or even recycling centres.
The technology used in SatLav is similar to that in modern GPS systems. The user simply sends a text message with the word ‘toilet’ to 80097, and a satellite pinpoints their location.
The satellite picks up the mobile phone’s signal and uses it to find the location of the nearest phone mast.
From that it establishes the post code in which the user is standing, which it sends to a database containing all of the toilets registered with the scheme.
The database then automatically finds a toilet that matches the postcode and sends a text message back to the user with the information. The entire process takes just seconds.
Robert Thurner, commercial director of mobile technology company Incentivated, which developed SatLav and maintains the database of toilets, said that the latest mobile technology was "making residents’ lives easier".
He said: "Whether they want to pay the congestion charge via their mobile or find their nearest recycling centres or licensed minicabs, mobile can offer an immediate solution, at any time and anywhere."
It is currently only available across 8.5 sq miles of Westminster in London and will cost 25p to use, with Westminster council paying a further nine pence.
The scheme could be rolled out across other parts of the country if it proves successful.
SatLav was developed by the council with Incentivated and is the brainchild of student Gail Knight, who entered the idea into a council competition.
Miss Knight, 26, said: "When I am out with friends we are always ducking into McDonalds or department stores to use their loos but we feel a bit bad about it."
She added: "I thought a text service would be really useful for people on the move."
Around 15 million people visit Westminster’s public toilets each year, while one million people come to the area every day.
The new service covers 40 council-run facilities and others run by the Greater London Authority and London Underground.
In addition, major Oxford Street stores including Marks & Spencer, John Lewis and House of Fraser have signed up to the scheme.
Westminster councillor Alan Bradley said: "From today onwards nobody should get caught short again, and we understand how important that is, be it for a young mum with children in tow, older people or friends on a shopping trip or a night out."
It is hoped that giving people a service to tell them where their nearest toilet is might also encourage them not to urinate on the street after a night on the town.
Westminster council already provides temporary urinals in the West End at weekends.
It estimates that this measure alone prevents more than 10,000 gallons (4,500 litres) of urine ending up in alleyways each year.