I find it illogical that on the one hand it couldn't be easier to buy a ticket on the web, even printing some off at home or having it sent to your mobile (am I right on that??) which is a fantartic development BUT on the other hand for a walk-on passenger, maybe travelling on the spur of the moment, may often face a battle of epic proportions just to make their journeys legal.
Every station should have a ticket machine, I think the Metrolink does and there are now dozens of stops, or have machines on trains (that's been argued for and against on here before!) so there's no excuse for not having a ticket.
The very cynical side of me makes me think that the TOC would rather someone pay the £80 penalty than the £8 ticket, so there's no, let's say encouragement, for TOC's to ensure guards/collectors go down the carriage or have working ticket machines. Now that's probably far from the case, but I bet I'm not the only one has those thoughts, and the only way for TOC's to remidy that is to simply...make it quick and easy to buy a ticket....then everybody's happy except the fare dodger.