This kind of thing should only be attempted by trained professionals hyped up on oatcakes and haggis:
Charlie's Diary: Being inclined towards crazy stunt performances, I'm planning on writing "Halting State" on my mobile phone. This is technologically feasible because the phone in question has more memory and online storage than every mainframe in North America in 1972 (and about the same amount of raw processing power as a 1977-vintage Cray-1 supercomputer).
It's a zeitgeist thing: I need to get into the right frame of mind, and I need to use a mobile phone for the same reason Neal Stephenson used a fountain pen when he wrote the Baroque cycle. Afters all, I want to stick my head ten years into the future. Personal computers are already passé; sales are declining, performance is stagnating, the real action is all in the interstitial networked devices that keep washing up on the beaches of our bandwidth ocean, crazy-weird things like 3G phones and battery-powered network attached storage boxes and bluetooth-controlled vibrators. (It's getting weird out there in embedded intelligence land; the net is alive to the sound of pinging toasters, RFID chips are the latest virus target, and people are making business deals inside computer games.)
The internet's old hat too, even with a second dot com boom (and bust) looking: in ten years' time we'll be up to Web 3.1415926535 and counting. Gibsonian cyberspace fits the picture about the way the US interstate highway system fits in a 1960s road movie. It's time to move on.