One of the interesting effects of such toys is that it helped kids form a clear picture of what they were capable of. I have a fairly accurate estimate of how high I can drop down from, how far I can jump etc.
Let me introduce you to the SomethingAwful RIPline: a DIY amateur zipline which could accelerate children to 65mph. The vertical drop was 143 feet. Had anyone ridden this thing they would have been pasted.
