[dexterdexter]

Segway! I'm surprised no one else mentioned this. The hype equaled the excitement it triggered on people. Personally, it signaled the arrival of the future at the time. Fast forward to today and they are just niche transportation devices used by tourists and to a lesser degree by some security officials.

[krapp]

The hype with Segway was high as long as no one knew what it was... for a while people were seriously speculating that it was an anti-gravity hoverboard like from Back to the Future or something just as exotic - but as soon as everyone found out it was just a scooter (albeit a slightly clever one), the hype vanished.