I'll just answer that!

Mobile telephony, 1990s style. I used this phone at work in the early 1990s.

If ever we doubt how fast technology is moving you just have to look back a few years and see how big everything was compared with today (well except televisions). This weighs a "tonne". How on earth I carried around I can't say, not to mention I could never get a signal (Well some things haven't changed!).