Monday, I tried to use one of our Garmin Etrek from work. It's not a unit designed for runners; we use it for GIS data collection, but it can display distance, speed, and time. I started it off, and took off. The intention was to do another 3 looper (2.25 miles). About halfway through the first lap, I noticed the Garmin died. Batteries were dead.
Since I didn't take a watch, I had no idea of time, but I felt like I was pushing myself. I ended up only doing two laps since I pushed myself, but that's cool. I've been leaning towards using my lunch runs to work on my speed rather than distance. There's just not enough time to get changed, warm up and run very far. I might start limiting it to two laps, and working on bringing down my time.