Even with limitations, I think it would be useful. From fixing mistakes that just happened, or going back to different decades to see how they actually lived and what life really was like!
Lots of people will probably say time machine, or molecular replicator to make anything, and hose would be great!
What I think would benefit society the most would be instant low energy teleportation, but through wormhole generation so we could use it for space exploration as well.
Tjink how mich the Internet has changed the works and brought communication to almost everyone. If travel
was no barrier people could live and work in different parts of the world and still be home to tuck the kids in for bed.
Families could keep stronger bonds, and I think it would be a tremendous boom for the economy and personal
growth for people.
- Saves time
- No Traffic
- No Pollution
need I say more?
Batman Suite - Everybody Like the kind of Lifestyle lead by Bruce Wayne. His Batman Avatar is Very Close to Real Life and Seems possible in Real Life so I like it a Lot.
Jarvis and Iron Man Suite - Jarvis is Great Technology, which seems real. Here also it Feels like IronMan is a Possibility in near Future.
Apart from that
Serum that made Captain America is Great Possibility without life extension.
Or this thing, If anyone remember these from MIB
The most logical answer would be a time machine .. the beenfit of hindsight always helps and we could have averted major international crisis like world wars .. world trade centre attacks.. Taj attacks.. and also use this to create a lot of wonderful good things for mankind. Hell we can even go back and kick out the British Raj and make us a better country
Telepathic communication in daily lives. That will be much faster than internet. Though it's not much fiction, still it's not fly developed
The sentient AI from Iain M Banks' Culture series are first-class citizens of society, polite and knowledgable. They can take the form of tiny specs, or giant hyperspace ships. I would love to live in a world where our culture was augmented like this.