I actually carry mine either in my CamelBack, or in my back pocket when on the trails. That said, I am a gadget/data geek, so I already have a computer mounted on my bars, and can see that data at a glance. The Garmin is really for post-ride data/mapping.

I have also used it for racing (MTB), but in my back pocket vs on my bars. To me, it is safer there.

SheFly