Submarine
In the book Twenty Thousand Leagues Under the Sea, the adventures were all in a submarine. While not everyone at that time knew whether this type of transportation would ever possible, it was considered fiction. However, today we have modern submarines that can do a lot more than just travel underwater.
Actually, one of the X-prize challenges:
https://en.wikipedia.org/wiki/Tricorder_X_Prize
#9 thats not the only thing about that movie that already exists
stun gun