EricNoah
Adventurer
I DM with a laptop -- it is off to one side on a little tray, and I use it to take notes during the game on a calendar spreadsheet and look up rules on d20srd.org. I rarely have to crack open a book during a game. I do use a computer for character/monster/adventure prep beforehand but I have those notes printed as I usually have to scrawl all over them as combat progresses.
One of my PCs is complicated enough that I use my laptop to deal with spells (using a spell spreadsheet so things are caluclated a head of time; and using a "die roller" spreadsheet to calculate huge handfuls of dice for damage) and conditions (keeping a running tab of what spells are cast on me so if I get hit with dispel magic I know what gets affected). But another of my PCs is simple enough that I use a printed character sheet for him.
One of my PCs is complicated enough that I use my laptop to deal with spells (using a spell spreadsheet so things are caluclated a head of time; and using a "die roller" spreadsheet to calculate huge handfuls of dice for damage) and conditions (keeping a running tab of what spells are cast on me so if I get hit with dispel magic I know what gets affected). But another of my PCs is simple enough that I use a printed character sheet for him.