A few weeks back, I took my Google Glass along with me to Costa Rica. I was able to fill our entire zip lining adventure in Selvatura Park near Monte Verde - a full 33 minute video - through glass.
Here's a clip of one of the higher legs - I believe it was 50 meters. I definitely reached some top speeds at first, but then the wind hit and really slowed me down - you can see me moving to the left-of-center toward the end of the leg as the wind pushed me from the right.
Also, at one point, I am able to catch a view of a nearby hanging bridge.