Walking around with a notebook (the paper kind, I like the small pocket sized ones with no rules so you can write music and draw things too) instead of a phone and then coming home and typing what you wrote into a computer is awesome. I wrote a memory allocator and a long form blog post while I was out the other day this way.

For a while I was writing a program to recognize a special kind of rune-like manuscript so the typing part is unnecessary but I realized it's less work to just sit down and type the stuff in. That's not too hard to get distracted from and it gives you way more flexibility.