Well Google will surely do it first. I've already edited code using my iPod touch, via a SSH client - it was slow because of the small screen and on screen key

Well Google will surely do it first. I've already edited code using my iPod touch, via a SSH client - it was slow because of the small screen and on screen keyboard, but I had to fix an error on the live site and had no computer to hand. I think you could easily code a whole site with VGA out and keyboard on a iPhone 4. Which could then be used from the device itself.