Remember the original Walkman? OK, that one's a bit of a design icon, but 80s mobile phones?
Here's my top five of 'things you think are cool, which the next generation are already laughing it.'
1. The iPod nano
See also any other ridiculously small gadget / MP3 player. We'll laugh that we thought they were small and we'll laugh that you actually had a separate gadget especially for music.
2. Keyless cars
You don't have to put a key in the dash, but you've got to have it in your pocket, so you've still got to remember to carry the thing. Seriously, if your car doesn't just recognise you, unlock the door, move the seat to your setting and cue up a custom playlist on the stereo, what's the point?
3. Facebook (no list of this type would be complete without it)
Crap at photos, crap at video, good at playing scrabble. Why did we spend so much time with this again? I keep banging on that Facebook's going to have a serious problem soon. When somebody connects people as effectively but gives them a better platform to do things (or connects different platforms) it's all over.
4. Digital Radio
UK radio will be digital only by 2015. Except it won't.
By 2015, we'll either be at or very close to a scenario where radio can be streamed easily via next (next) gen 3G mobile or wireless. When that happens, what's the point in digital radio?
Spotify is already there, the technology works.
Remember when movies came on disks and you had a whole shelf full? Hilarious!
Compared to a download to whatever is plugged into your TV in a few years' time, Blu-ray is fragile, cumbersome and expensive.
Netbooks belong on this list too, but it's a top 5. Got any more?