If you read the article it lists the things he took. Maps etc didn't appear to be a part of it. I would say his phone did the majority of the navigation.

I doubt that phone + battery + solar charger is going to weigh less than a compass and a few sheets of waterproof maps. Since you have to resupply at points along the trail, you don't need to carry detailed maps for the entire route in your pack.

I personally wouldn't want to rely 100% on a phone. It would have to be ruggedized, you would need a way to charge it daily, and it would have to have all the maps (which for this purpose are detailed topographic maps) stored locally, as there is no cell coverage in a lot of wilderness areas.

Most of the time on the PCT, maps are superfluous. The trail is well defined with clear signs. Even so, it's always a good idea to pay attention to where you are and what the area around you is like. If something goes wrong (injury, medical emergency, wrong turn at Albuquerque), that knowledge could save someone's life.

I can't even imagine taking my phone. One of my favorite parts of backpacking is not looking at an LCD screen for 10+ days.

PCT is trickier to navigate. You don't want to go without a regular compass. Many I have talked with say the guide books are good, but they needed additional maps for some sections. Its especially tricky when the snow is covering up parts of the trail and you just have to guess it. I dunno, I think you can avoid the phone and come out about the same.

Yes. A full set of maps [1] takes about 455 pages, approximately 3 pounds double-sided. You don't want to carry all of that at once, but rather break it into sections and have someone them to you along the trail. I carried paper maps last year, a few sections at a time, but would have been fine without.

Many hikers in 2014 carried only a smartphone and solar charger (or external battery) for their navigation, camera, journal, flashlight, music, and so forth. The smartphone apps [2] that use Halfmile's GPS data [3] can easily get you from Mexico to Canada.

The sCharger-5 [4] is the unofficial solar charger of the PCT, I carried one last year as did many others. The West coast is sunny enough that you attach it on top of your pack and have 5 volt USB power most of the time.

[1] http://www.yogisbooks.com/pacific-crest-trail/halfmile-map-s...

[2] https://play.google.com/store/apps/details?id=net.tadteam.ha...

[3] http://www.pctmap.net/

[4] http://www.suntactics.com/product/usb-solar-charger-5/