Unless you can skillfully bounce it off his head and away down the field, throwing the clock at your opponent will only make it quicker for him reset the clock and play his move.
Naturally, protective equipment should be worn and special padded clocks should be used.
When I was taught chess (at age 7), some old players (fifty years and older) I played with had weird rules --they were not weird to me then: (a) On the first move of the game, instead of moving a pawn two squares, you could move two different pawns one square each (and only on move #1); (b) you can promote a pawn only to a piece you have already lost (e.g., you can't have two queens on the board); (c) you could not take an opponent queen by accident, you had to: checkmate it, or the opponent declare it a sacrifice/gambit and allow it, or exchange a queen with another queen. These games were fun.
When a player played against a weaker player, he (or she) could allow him to take a piece other than the king or a pawn (e.g. take out a rook, or a queen, or a night, or a bishop, or any two pieces. The more the difference in skills, the more pieces are allowed to be taken out by the major player. Another way to equalize difference in skills was to allow the weaker player to make two moves for each one move of the skilled player during the first 5 (or 6, ... or 10) moves of the game. These techniques allow a skilled player to enjoy a game of chess as he/she 'teaches' a weaker player.
The en-passent rule in chess could use some innovation: either scrap it or: (a) allow any piece to take a pawn en passent. We could also allow the pawn moving two square to check a king (which has to move) even if the pawn landed on the second square that does not check the King! (e.g moving a pawn from c2 to c4 when the enemy king is at d4 would cause a check and force the king to move.
When the two players can't force a checkmate (a case of a draw), how about changing the rule so that the king who reaches the first row of the opponent side (where the major pieces are) wins the game?!I like to avoid complex rules, but here is another idea. How about the king has a heir (e.g. a loved son/prince) who is one of the king's pieces on the board other than the queen (a pawn, a rook, a knight, or a bishop). Each player declares on piece of paper (or to the computer), which piece is the secret prince. At the end of the game, each player reveals his (or her) secret prince; if this piece was lost during the game, the opponent gets a point (it is like a win). This rule would make a player favor a certain piece and protect it without letting the other player notice who is the prince! If this piece is lost during the game, the opponent wins a point at the end of the game when the prince is revealed. Each win could count as 2 points if the king is checkmated and the prince is taken out during the game! What do you think? (This reminds me when Prince Harry of the UK served in Afghanistan in 2007 in a secret location and was pulled out in 2008 when it was published where he was).
Once a game you can take a hammer (which is placed by the table) and bang it on the chess board. Any of your opponents pieces that are thrown of the table are out of the game. Any your pieces that fall of the board are traded in for green rooks (refer to solskytz for instruction on green rooks). If the board breaks the opponent buys a new one.