Oooh, I'd forgotten that I have one, and never use it. I've actually had it a couple of years, and only used it once

It's a HEARTalker personal trainer heart rate monitor. It straps across the chest and has earbuds so you can hear it tell you what your heart rate is, and it also provides workouts and motivational messages.
The surprise? Well when I ordered it, I didn't get a choice of models, and the voice happens to belong to a well known (nameless lol) fitness expert with a very annoying voice! I think that's why I never used it after the first time, lol. I'll dig it out of my desk and give it another shot.