Random Riddle: Superman’s Dilemma

It used to be
that in a time of need
for the minimal price
of the dime you cede
I would stand ready
with a book you read
to find a number
which can be keyed
which connects you up
with relative speed
to someone with whom
you could beg or plead.
And if you are lucky
they may take heed
and from your troubles
you will be freed.

What am I?
 

Random Riddle: Superman's Dilemma