Long ago, when designing websites, the developers would have the code open in their editor, and two web browsers (Internet Explorer and Netscape Navigator). If the site didn’t work fully in both browsers, then it was either back to the source code or pop up the helpful message that ‘this site only works in Microsoft Internet Explorer 3.xx or greater.” If the industry isn’t careful, the same helpful error messages could cause frustration the world over.

Look at the wide range of form factors that are coming out of the manufacturers. It takes just a few minutes surfing to find a huge variety of form factors. There’s the clamshell device (such as Nokia’s E90) that looks remarkably like the PDA’s we all used in the late 20th century; smartphones in the standard flip or candy bar modes, Blackberry inspired devices with full Qwerty keyboards for your thumb, and a number of innovative hinges and designs (such as the Sidekick 3 or the Nokia E70).

All of these are obviously ‘mobile messaging’ devices, but with a variety of form factors, not least in the size of the screen, where the user could be running on anything from a 128×128 interface from Nokia up to a Windows Mobile 640×480 VGA screen. How they deliver the message to a variety of devices is one of the key challenges in the new mobile space.

But the fun (or as the Design Departments might refer to it, the headaches) doesn’t stop there. There’s nothing that says that Mobile Messaging has to be restricted to mobile phones – and while the ability of your fridge to browse the internet was something every business plan used to consider, that’s starting to become a practical consideration.

Microsoft’s misfiring Spot Watch had the ability to receive RSS feeds, and that opens the door to a huge amount of potential – having alarms on your watch not because of an appointment in your diary, but because they’ve walked into your house in Second Life, or the impending end of an auction in Ebay, or even your Twitter stream redirected to your wrist are possible.

Add a high speed data card to your laptop and is that a mobile messaging device? It might have all the power and flexibility as it would connected to a home or office wi-fi network, but slower speeds, and a heavier focus on the bandwidth used means that special considerations could be needed from the user, or a suitable ‘smart’ web service.

And while it’s not quite the white goods takeover, the latest generation of games consoles are getting in on the action. The Nintendo Wii’s web browser brings the internet to television screens across the world – Google have recently announced a Wii-designed page for their Google Reader product. Sony’s Playstation Portable contains not only a Web Browser (Access Netfront, compared to Nintendo’s courting of Opera for the Wii and the DS), but a full blown RSS catcher for podcasts and videocasts that’s happy to update all your feeds automatically at night for your commute in the morning. It’s probably the best commercial podcast device currently on the market.

So it’s not enough to have the perfect Mobile Messaging 2.0 idea, you now have to sit down and work out which market sector you’re going for. It’s unlikely that you’ll be able to come up with a one size fits all approach in the modern world, so you’ll need to compromise the platform reach (through device targeting) or available features (to run on the lowest common denominator). I’m very interested to see just how this multi-platform issue is going to be addressed.