Wired on Friday: Here's a question. What's the one media platform you could not do without? The one thing you carry with you and look at constantly, at home, on the train, in the car, walking to the shops, even read on the loo?

Is it that new celebrity-packed magazine? Is it that television news show, even video copies of which you carry around and replay incessantly? Is it that portable radio or TV? Do you take a broadsheet to bed?

The answer of course is none of the above. But I can guarantee you will behave in this way with your mobile phone. And yet, despite this near 24-hour relationship we have with our mobiles, there are media owners and advertisers who continue to ignore the mobile arena.

Our mobiles connect our personal and professional lives. Sometimes they are the physical manifestation of both those threads of existence. Today's mobile is the receptionist, call centre, email access point and the Friday night party planner.

Globally, mobile phones now outnumber conventional phones - 1.3 billion mobiles are in use worldwide versus 1.1 billion land lines. And all of these devices - from the humblest Nokia to the most expensive Blackberry - are crying out for media and content.

According to a July report from Wireless World Forum, the mobile content markets of Europe and North America will grow from €1.8 billion in 2003 to be worth potentially €4.3 billion in 2006. The largest growth will occur in the mobile games and downloadable music markets, which could collectively see growth from €510 million in 2003 to over 1.9 billion in 2006.

More than one eminent thought leader in the media sphere has pointed to the inexorable future of mobile digital media. Speaking at the Seybold-Roman Future of Print Conference, Mr Vin Crosbie, managing partner of the influential consultancy Digitaldeliverance.com, thinks "by the end of the decade, you're going to see electronic books, papers and magazines".

The question is, how is that media going to be delivered? In an SMS text, a multi media message (MMS), on a WAP page or on an i-Mode phone? Some will already be acquainted with the staggering explosion in the use of the SMS service. According to the Mobile Data Association, the number of person-to-person text messages sent across the four UK GSM networks in July this year was 1.68 billion compared with 1.3 billion last year.

On the back of this interest, many media owners and advertisers have launched SMS text services. Photo and video messaging and services, too, are patently on a growth curve.

How long is it before advertising and sponsorship deals are put in place where full-length songs, pre-release singles will be able to be sponsored by major brands, tapping into the associated caché for the youth market?

Vodafone Germany has already launched a service that sends the MTV Top 10 videoclips as Video MMS messages to Vodafone clients each Monday for €0.99. And just recently the UK 3G operator 3 signed a similar deal with MTV.

But while the growth of messaging has defied all expectations, what of the mobile portals? The early indications are that WAP and the mobile internet has not been as successful as some had predicted during the white heat of the dotcom boom. Only about 9 per cent of European mobile phone owners went online with handsets in April 2003, up only 1 per cent from June 2002. In the US the figures were flat at 8 per cent. Is it something to do with the way WAP has been marketed, delivered, or the amount of WAP media content which is available?

There are platforms out there that are making the mobile internet a viable medium for media owners and advertisers. But half the time they don't call it a WAP portal and avoid blinding consumers with jargon.

Vodafone has been successful enough with its Vodafone Live! service, which eschews technological talk to concentrate on services and content, and has attracted 1.5 million users across Europe. In Europe, the experience of i-Mode, a mobile-friendly version of the Web, shows that it is possible to serve oodles of successful mobile media. Some 600,000 people use i-Mode in Europe, and that number could more than double by 2004.

In an astounding statistic, mobile advertising on the i-Mode platform operated by Japan's DoCoMo mobile network will soon exceed the amount spent in advertising on all of Japan's radio stations. This has been achieved in an amazing five years since i-Mode's launch.

We already know the ability to text a number in reaction to an advertising campaign across any media. But more methods are on the horizon, such as mobile users interacting with traditional advertising.

There is already the tried-and-tested experience with SMS voting on shows like Pop-Idol. And last year UK-based Hypertag.com announced a system based on smart tags that can beam website links to mobile phones via infra-red to give people more information about a poster, advertisement or shop. The future looks interesting.

But this mobile market will not be a walk-over. Like the early years of the internet, the publishers and advertisers that win in the mobile medium will be those experimenting now - before the rest of the industry has mastered the new medium.

Mike Butcher edits mbites.com, mike@mbites.com