Who are you, and what do you do?
Paul Graham. I write essays, work for Y Combinator funding and advising startups, work on a new Lisp dialect called Arc, and administer a site called Hacker News, which is written in it.
What hardware do you use?
What I actually sit in front of is a MacBook Air and a 23" Cinema HD display. I also have a server running FreeBSD on the east coast, but that's going away soon.
And what software?
I use surprisingly little client software. All I really use on my Mac is Firefox and Terminal. I use the usual Unix utilities (vi for editing). I use Arc for programming, which in turn runs on top of MzScheme. I use Dropbox for syncing. Online I use Gmail, Google Calendar, Etherpad, Snipshot, Picwing, and, believe it or not, Yahoo Store for managing my site.
What would be your dream setup?
I'd like it if the Air was about half the size. I don't know why Apple won't make something in between the Air and an iPhone. And of course I'd like to have infinite amounts of memory and an infinitely fast CPU.
I'd like it if the HD display was bigger and much lighter and didn't have such a massive octopus of cables attached to it. Then I'd be inclined to move it around more and work in different places.