You are at a party and announce that you have a friend who is such a great psychic that he can tell what...

magic/card/guessing.over.phone

Problem

You are at a party and announce that you have a friend who is such a
great psychic that he can tell what card someone picked out of a deck
via the telephone.

You then get a pack of cards and ask for the group to select someone to
pick a card from the deck.  At this point there are two variations: 1)
If you know how, you can force a card on the person or 2) you can
spread the cards face up and let the person pick one.  Then you go to
the telephone and call your psychic friend.  You say "Is (name) there?"
followed by "(name) this is (your name)" and finally "(name) will you
tell (selectee's name) what his/her card is?"

The friend then correctly identifies the card.

Show solution

As soon as you ask for the friend, they start saying "Ace, two, three
...." with appropriate pauses.  When they say the correct card, you say
"(name) this is (your name)".  They then start with "Spades, Hearts,
Diamonds, Clubs."  Upon the correct suit, you ask them to reveal the
correct card.

Variations:

The strongest variations on this are the FORCED CARD and the
predetermined name.  There are two variations of the forced card.
First, there is the predetermined card, e.g., the 7 of Clubs on Friday,
the 10 of Spades on Saturday, and the Queen of Diamonds on Sunday.
Under this scenario, you must force a specific card on the selectee.
Second, there is the situational forced card.  In this case you have
forced a card, but nobody realizes that you know what the card is.  The
first FORCED CARD variation is exceptionally strong because you can do
it on a speaker phone.  The second variation is strong because nobody
realizes you know the card.

The predetermined name variation is the most effective because you get
the same results without forcing a card.  Each suit needs a first name
and each card needs a last name.