Now, please don't write me off as a 'boring old fart'. OK, so I probably am one, but that shouldn't discount my opinions - and I have used almost every phone and PDA from the last 15 years, so my thoughts should count for something. The subject under discussion here is Touch and my conclusion so far is 'Unconvinced'....

The first touch-based PDAs appeared in the mid 1990s, with Palm's stylus-based PDAs, closely matched by Psion bringing in touch into their EPOC-powered palmtops and then Windows Mobile (nee Pocket PC) joining in the fun around the millennium. EPOC mainly evolved into Symbian OS, running the S60 and UIQ interfaces, with the former unashamedly button-driven and the latter unashamedly stylus-driven.

Despite the relative success of Palm's PDAs, I think it's fair to say that the reliance on using a two-handed, stylus-driven interface meant that none of these touch-screen devices really became totally mainstream, in the sense that you'd see your mum or brother or colleague using one with no encouragement from you.

And then the Apple iPhone came along. Its main innovation was that it dispensed with the conventional wisdom that touch meant a stylus and allowed the use of a grubby, greasy, uneducated finger instead as its main driving force. You still had to use two hands (most of the time) but at least one barrier to use was removed for the main in the street.

A secondary innovation was the capacitive technology, meaning that a touchscreen could, for the first time in years, actually be viewed in sunlight and was incredibly responsive to the slightest touch. Backed by a ground-up interface rethink and Apple's legendary 'cool', the iPhone became a deserved (if rather high end) success.

With the result that most phone manufacturers have now jumped on the 'touch' bandwagon, trying to emulate the iPhone's success, or at least its mojo. Even Nokia now has touch as one of its cornerstone interface technologies for 2009, with the 5800 XpressMusic and N97 both sporting the fully touch-enabled S60 5th Edition.

In an attempt to try and understand whether either will take off in the real world, I had been using the 5800 as my main phone/device for the last two weeks. But I've just put my main SIM back in the Nokia N82, with the aforementioned 'unconvinced' as my verdict.

On the face of it, to get the latest and greatest version of S60, plus an iPhone-like caressable interface on a lovely large screen, plus a decent (if unspectacular) camera and some seriously loud speakers, all in a body the same size as the N82, seemed a bargain and certainly the sheer novelty factor kept me hooked for at least a week. However, there are numerous problems, not all of which can be solved by firmware updates:

• firstly and foremostly, touchscreen interfaces are superb when you're unstressed and with both hands free. When you're on the move, either in a car (with the device properly mounted on a stand, of course) or walking down the street or on a bus or train, there's too much external vibration for accurate use. You reach for an on-screen button but either don't reach the screen or hit the wrong icon, ad infinitum. All the time wishing for a physical d-pad or keypad that you can feel and manipulate even without looking, if needed. Sorry, Nokia, Apple and so on, haptic feedback doesn't hold a candle to physical control and character entry keys.
   
• the touch implementation on the 5800 XpressMusic (and presumably the upcoming N97) is flawed in that icons often don't respond to tapping and have to be tapped again - this should be fixed in firmware soon.
  
  
• text input using the on-screen keyboard is slow because of the use of a resistive touch-screen, meaning that only one character can be tapped at a time: tap, release, tap, release, and so on (c.f. the iPhone's multi-touch meaning that you can go as fast as you like) - writing/spelling aids in a firmware update might help alleviate speed concerns here - we'll see.
   
• the resistive screen is hard to see in strong light - it's as good as resistive gets but it's only marginally useable when using in direct sunlight.
   
• the resistive screen  also requires significant pressure - this is most noticeable and unpleasant when dragging web pages around in Web. With Samsung adopting a capacitive screen for their S60 5th-powered Omnia HD, resistive touch technology is really looking rather old fashioned now.
   
• finger-touch interfaces rarely take into account the way a fingertip 'spreads' at the point of contact. In practice this means that wrong icons, characters and options get selected, with time wasted as you back out of whatever you just went into by mistake.
   
• a full-screen touch device is necessarily more fragile. Not in a 'it might break' sense, necessarily, but in a 'have to treat it with extreme care' way. Your kid wants to play a game on it - got to clean those greasy hands first? Want to put it out on the pub table beside you, getting showered with beer splashes and crisp crumbs? Want to just stick the phone in a pocket? Must make sure the pocket is free from dust, dirt, crumbs, keys and so on first. And if dirt does get on the screen, your next page drag in Web might gouge the surface permanently. Resistive touch screens have always been this 'fragile' - witness the number of screen protection and polishing kits available from the days of Psion and Palm onwards. The strong glass display of the iPhone and other capacitive-screened devices are better prepared for the onslaught of real life and much easier to clear/protect.