On his blog, Terence Eden wrote about the Time I Invented Twitter and it's an interesting proposition which would have just been slightly ahead of its time in 2003. Microblogging probably needed Internet enabled phones to take off, like social networking in general.

Douglas Adams was a very intelligent man who liked his gadgets - Macintoshes, synths and left-handed Casio guitars appeared in the first Dirk Gently novel, Dirk Gently's Holistic Detective Agency, and, with The Book in The Hitchhiker's Guide to the Galaxy he, at the very least, created the idea of a portable device that knew everything.
When the commercial Internet started, Adams got involved in games, co-founding The Digital Village, developers of the game Starship Titanic, who then started h2g2, a collaborative dictionary project described as the Earth edition of the Hitchhikers' Guide to the Galaxy.
In his article My Vision for H2G2, written in 2000, he wrote this:

...when you write in something as simple as 'The coffee here is lousy!' the Guide will know exactly what to do with that information and where to put it. And if you see, a few seconds later, a note which says 'Yes, but the cheesecake is good' it might be worth looking round the other tables to see who you've just made contact with.

That resonated with me, and I filed it away. At the time I had a kind of mobile Internet setup, with a Palm V and a Nokia 8210 that communicated by infrared, that I could actually browse the web on, and with a bit of coaxing even use telnet on. Given this experience with the mobile web, I got tipped off about a trial project that involved the Handspring Visor, a PalmOS device that improved on Palm's hardware by adding an expansion slot, that among other things, had a GSM phone module and a TCP/IP stack (my memory says it was actually Trumpet Winsock ported to PalmOS, but my memory sometimes makes things up). For £99 and couple of feedback sessions, I had a connected handheld device.

At the feedback session, they walked me and other trial users through what they had in mind, and from what I can remember, it was fairly grey stuff. Online banking seemed to feature quite a lot, and it turned out that the service was rather limited by the data provider and a relatively high cost for data at the time. It might have even been limited in availability from 8am to 8pm or something like that. Given the lack of ideas coming from the company, I quoted DNA's idea above, which seemed to me to be a logical progression, and it seemed that the idea had never occurred to the company.

The project was abandoned. I heard later that the running cost was unpopular - data pricing was on top of airtime, which wasn't cheap back then, but also that the applications they were aiming at just didn't catch the imagination. I held onto the Visor for a while but it more or less died when PalmOS died, and by the first generation of genuinely smart handheld devices were starting to appear.

To embrace that in 2003 was to look forward from blogging, which, let's not forget, was huge then, to something much more personal, but also that would as Adams imagined, hopefully add to the sum total of global knowledge.