It was 2001 (remember pre-smartphone life? Bring your map!), and I was designing a small touchscreen keypad for an in-vechicle messaging system. I'd recently finished my Biomechanics/Ergonomics master's thesis measuring muscle activity on physical keyboards, and after double-checking the anthropometric charts for touch size standards, I realized the screen was too small to make all keys the recommended size.

Then I thought, "why should all the keys be the same size, when we use E waaaay more often than Z, for example?" So I looked up letter frequencies and found that in English, we use just 9 keys about 80% of the time. Since different-sized keys can't be arranged into a grid very well, I figured I might as well put the most-used keys together, and put the most common letter combinations ("bigrams," like TH and ER) next to each other.

I was pretty proud of my solution, but when I presented it to the engineering manager, he was like "WTF?" and implemented a simple QWERTY grid. Sigh. But the seed was planted.