I've heard about one system called "Timtoo timing". I believe it works like this: You attach a chip to your bike, and sensors on certain climbs let you record your time. Of course, this is just like in an organized race, but the special thing about this is that the sensors are there permanently and you can go and do it at any time. I've never used it, and I'm a little vague on the details, but it sounds interesting. However, looking at the
Timtoo timing website, it appears that they only have such set-ups in the French Alps and the French-speaking Swiss Alps. Therefore, maybe the setup you saw is a similar thing run by a different company.