Casio might be only lightly involving itself in the current boom in smartwatches and wearables, but the company still makes plenty of money from its G-Shock series and rugged outdoor watches. That's not to say it hasn't experienced a combination of hits and misses: Casio would say it "pioneered" a huge array of features in its digital watches over the decades, many of which have returned -- in a more appealing or functional form -- in smartwatches today. It crammed GPS into a watch in 1999, lashed a rumble-pack to its early gaming watch and even made a waterproof watch that warns you've been out in the sun too long. And that's just the beginning. Smartwatches may be capable of much more, but credit is due for how Casio was tackling these features decades (too) early. Niche? Yes. Fascinating? You bet.