For a start, however dinky and cutely coloured, your mobile phone is suspect. The reason: not only does it help you keep track of your friends but, when turned on, it also enables anyone interested to keep tabs on you.

The phone does this by broadcasting an ID number to the closest antennas, which enable the carrier to identify its customers. It is just a question of triangulation - tracking the signal as it hits various towers, then calculating the device's position based on time differences.

When you surf the Net, you are exposing yourself to scrutiny, too. Despite the playful graphics Google employs, it is watching every move you make and recording it forever.

This means its database of users' searches could prove handy to police and divorce lawyers, the parties under investigation frustratingly incapable of deleting their search history.

The so-called surveillance society is no longer just about cameras, but they are still its mainstay.

Venture into the Soho district of central London on the fringes of Chinatown and you are under constant surveillance. In fact, any where you go in the land of liberty, you are likely to be filmed, since it is said to be the world's most heavily scrutinised society - the average Briton is already filmed by about 300 cameras every day.

Filming has become as prevalent through an insidious process I tracked through my childhood. As cameras spread from shop to shop, initially the closed-circuit television (CCTV) images were grey and grainy, making the presence of cameras little more than symbolic, a way of saying 'Watch out'.

The clunky boxes, however, evolved into sleek tubes offering colour footage. Correspondingly, the definition sharpened.

Now you see yourself as in a mirror and can check how much hair you have on the top of your head - mesmerising and more than a little disturbing.

So, too, is the emergence of the flash-enabled camera, or flashcam. The reverse of a covert camera, the flashcam is a proactive tool meant to deter or stop graffiti, vandalism and illegal trash dumping.

But the average CCTV camera is as discreet as a door handle. The prevalence of lenses encourages us to forget that our privacy is being eroded to the point that it now has near-joke status, like voluntary service, chivalry and other quaint concepts.

The slogan 'Privacy, what privacy?' sums up the mood. We seem to be inching towards the panopticon: a type of prison designed by the 18th century British philosopher Jeremy Bentham.

The design enables a centrally-placed observer to see all prisoners, conveying a 'sentiment of an invisible omniscience'. The British writer George Orwell reconfigured the panopticon as Big Brother: the dictatorship at the heart of his prescient novel 1984. How ironic that the two most famous prophets of creeping intrusion hailed from today's most monitored nation.

US-based analyst David Brin, author of The Transparent Society, proposes a 'Moore's Law of cameras'. He sees them roughly 'halving in size, and doubling in acuity and movement capability and sheer numbers, every year or two'.

In other words, rather like a malevolent virus, their numbers will explode as they continue to mutate.

Another of Mr Brin's predictions is the development of rolls of ultra-cheap digital eyes we can stick on to walls, making our presence felt on the internet protocol version 6 (IPv6). This is next-generation internet that will increase the number of available Web addresses, resolving the problem of the surge in computers hooked up to the Net.

'Millions of those 'penny cams' will join in the fun, contributing to the vast IPv6 data sphere,' Mr Brin writes.

Adding to the fun, many computers, such as the new Macs, sport inbuilt cameras. All you need is spyware, and presto, you are being watched.

Expect surveillance technology to keep mutating and growing ever more sophisticated because it seems to have irresistible momentum bolstered by the assumption that the innocent have nothing to fear.

The advance of biometric technology means you can now be identified by your fingerprint, your iris, even your gait. Defense Advanced Research Project Agency's yet-to-be-perfected gait-analysis program aims to identify terrorists by the way they walk. Soon, we may be recognisable by how we smile and smell.

Not that we will have a chance of noticing we are being watched, even if we try. The reason: in what is known as pervasive surveillance, spy devices are shrinking to the point that they will become invisible to the naked eye. Miniaturisation means they can be stuck almost anywhere, becoming part of interiors - even clothes and bodies.