One of the niftier gifts I got this past Christmas was a Garmin Nuvi. But I wasn't the least bit interested in sticking it in my car to get directions—no, I wanted instead to use its GPS-derived peak speed feature instead.
The Nuvis give you a continuous (and pretty impressively accurate) speedometer that you can use to measure yourself doing just about anything. Such as, settling once and for all a long-running discussion between my brother and me, both of us former Alpine racers, which is, just how fast do we ski, exactly?
So, since I'm currently skiing in my hometown of Flagstaff, AZ, I took the Garmin up the slopes today and measured myself at my typical Arizona Snowbowl cruising speed, which is speedy but certainly not Colorado speedy.
The verdict? On the flats I typically buzz around 30-35 mph, and on intermediate pitches, I bump up to around 45-50. These would be cruising speeds, ie on groomed empty slopes where I feel comfortable letting the boards run. Still, on the whole...kind of fast. It's interesting to compare my speed on skis versus bicycle. 11-15 mph feels just fine to me on a bike, thank you, and I basically ride the heck out of my brakes anytime there's a downhill.
If you're wondering, in the backcountry I'm a very different skier. My goal when I'm not in the protective womb of a ski area is to never fall, ever, for any reason. So my speed—and my attitude—get adjusted accordingly. That is all.