10-20 mins bike ride via bike share - I use Overcast to listen to podcasts at 2x+ speed, shorten silences, and voice boost. Since I'm biking, somehow the speed of bike matches really well.
On Caltrain, I tether my wi-fi. If you're on the fastest bullet, don't bother trying to get internet, it doesn't work. Otherwise, the moderately fast bullet or the regular trains will give you reasonable internet to answer email.
Oh, I also use VLC with a tv show or movie and watch at 1.25-2X speed so that I can watch a whole thing in a fairly short span of time. You'll realize it works pretty well.
Additionally, I swear by Pocket (which also reads articles to you), Voice Dream (which integrates with a bunch of other things and can read to you as well at a fairly fast clip). If I'm reading, I'll also use the Kindle app or potentially have my Kindle with me.
If I'm reading an online article, I've been trying to train myself with Spreed so that I'm reading faster.
I've seen others just play games on their mobile devices or use dating apps - both of which seem to magically make the commute disappear.