Cell phone and smokes. :thumbsup:
I use a Daytimer for most of my stuff--mileage log, receipts, various computer printouts and so forth. Proposals being hand-delivered get a presentation folder. Site-walk notes get scribbled on a cheap spiral bound pad and entered on the computer at the end of the day.
You really have to define the circumstances for any answers to make much sense. I'm in small-job mode these days, with no need for extensive databases or high-end pictorial presentations. If you're into high-end work and/or manage multiple jobs and crews, that's a whole different ball game.