The good news is, of course, that a few well-chosen apps can substitute for destination guides and navigational help. The bad news... there's still a lot of stuff to bring along. Here are five-plus apps I loaded specifically for this trip, and a few hardware items that I couldn't do without.
As many times as I've been to San Francisco, I still don't have a firm notion of the city's geography outside the immediate vicinity of Moscone Center (don't blame SF -- I still get lost in my own home town, too). To help me get around, I've tried iBART, BayTripper and the free, location-aware nextbus.com mobile site.
Still, I come back to two tried-and-true tools every time. For public transit and walking directions, the Maps app does a great job; bus timing may not be precise, but you get where you're going. If your transit needs are a little more personal, the astonishing Taxi Magic app gets a ride to wherever you are in no time flat -- and with no additional fee, if you pay in cash. Honorable mention: the Zipcar app, if you need wheels of your own in a jiffy.
Before boarding the plane to come out to the West Coast, I checked that my two favorite air travel apps were loaded and ready. The Tripit app (paired with a Tripit Pro subscription) keeps my itineraries right at my fingertips, including the ability to search for alternative flight reservations. While I'm hopping through the airports on either end, Gate Guru helps make sure I don't skip past the best place to eat while I'm meandering towards my gate.