drinking game - the name game

you need:
4+ people
knowledge of pop culture
heapsa drinks

-the object of the game is to say the names of famous people, bands or characters.
-you must drink while you think.
-to determine the letter for the next players turn, you take the first letter of the last name from your turn.
for example, if player A says micheal jackson, player B has the letter j for their turn.
-if both names begin with the same letter, then the flow of the circle is reversed.
for example, if player A says micheal jackson, then player B says janet jackson, it is player A's turn on j (as opposed to player C).
-if a said name is only one name, then the final letter of that name is the first letter for the next turn.
for example, if player A says madonna, player B is on the letter A.
-once a name has been said, that name is not valid for the rest of the game.
-players who are not having their turn may say any name (and thus invalidate them for the rest of the game) at any point.
-its the next players turn when you think of a name or finish your drink. whatever comes first.
-half of all players must know a name for it to be valid.