I hit an issue with using my iPhone to track my rides this weekend when I did my first ever semi-longish route (42 miles). In that the battery was draining dangerously and if I kept the GPS tracking going the entire ride instead of just the first 17 miles or so it would have died completely. As it was, I ended up at under 5% battery by the time I got back home.

I'd love to get a dedicated garmin unit for that purpose, but it's pricey. So I settled on the good ol' wheel rotation based computer and called it a day until I can spend the cash on something more sophisticated.