When ideas that have never been successful keep coming up over and over again it's usually because they simply haven't been implemented right and are just waiting for someone to think up the right sauce.
Ambitious successful technology is usually a culmination of decades of failure. For example:
1. Touch screen computing (iPad)
2. On-demand video (YouTube, Hulu)
3. Video phones (Skype)
4. The all-in-one fits-in-the pocket pda/phone (Android/iPhone)
If you talked to say, a YouTube exec in 2004 about their ideas you'd probably walk away thinking "Oh yeah, that idea; the one that has failed so hard, so many times, that I was looking for the hidden cameras".
And you'd be dead wrong.
This isn't new, if you go back 40 years you'll find that Credit Cards, Bar Codes, ISBN numbers, the home theater, all had predecessors that sucked. Even the personal computer and the home video game system had years of failed starts.
