Mark Weiser:
"The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it. "
http://nano.xerox.com/hypertext/weiser/SciAmDraft3.html
Like transistor radios, how they were called way back in the 1950's. Later just radios. And nowadays those radios are merged to mobile phones and other apparatus. Making them invisible, immaterial memory of something that used to be concrete to us. Like leverage, downshifting, bottleneck, ...
One could argue that the more profound the technology is, the harder it is to distinguish from the realm of every day life.
