I agree that in some capacity, everything mentioned here certainly helps.
But to be honest, I have personally found success in all of my high school classrooms at encouraging a reading habit by providing exactly two things: (1) books the students are interested in, and (2) time to read.
That's it. The magic formula.
Technology had absolutely no part, though I don't discredit that there are a lot of great websites available to help students find their reading likes.
Parental involvement (at the HS level) had very little part, though, I admit most students who do read for pleasure habitually, also have parents who read for pleasure.
I think at our core, humans are naturally inclined toward stretching our imaginations, increasing knowledge, and finding pleasure in reading. This generation of learners has simply had such a gift replaced by TV, iPods, cell phones, parenting techniques which encourage over-stimulation, and general busy-ness.
I didn't have much time for pleasure reading in HS. Between homework, extra-curriculars, family, and sleep, reading was the first thing to go. But if there had been a 45 minute slot during school once a week, I would have relished filling it with pleasure reading. If we provide the time when there is no time, and convince students that good books do exist, I really think most will come back to reading at a point in their lives when their schedules allow for it.