Tricorders
Star Trek did have those relatively small hand-held computers
back in the 1960s.
One little-known feature of those original tricorders is that they
had a compartment just below the screen for holding small data
recording disks.
Imagine if that had been known/shown more widely, we might
have had CDs and DVDs even sooner.
http://memory-alpha.org/en/wiki/Tricorder
After all the makes of the floppy diskette said they were partly
inspired by the flat data squares Spock used to insert into the
science station's computer.
http://en.wikipedia.org/wiki/Tricorder