As a former referee, i can give you a precise reason why you cant use TV technology for incidents like a ball crossing the line. Football is hte only sport that doesnt stop when a potential "point scoring" situation occurs. In tennis, when you win a point, the player can then object and before the next point is played for they can analyse whether the point was awarded fairly. In cricket, if a player is judged out, before play is started again, the umpire has the ability to check whether his decision is right or wrong. In Rugby when a try is being debated, the play has already stopped, and before play recommences the referee can analyse whether it was indeed a try or not. In football however the play doesnt stop. If a ball bounces down off the crossbar, the play isnt stopped so the referee doesnt have the chance to analyse anything. The only way you can perform a check owuld be the next time the ball wasnt in active play, which in some cases could be ten minutes later. If the play was stopped when there was a dubious situation, then it could mean the defending team who have hte ball in their posession have to stop, the referee then realises it wasnt a goal, and they have lost their momentum, thus they've been penalised unfairly. Let me give you a prime example of why it cannto be done United v Spurs 2005. Carroll drops the ball and it goes over his own goal line. Everyone could see it was a goal, but the referee.. Play continues.. Supposing United then go upfield and score. The ball then is dead and at htis point the referee has a chance to see whats really happened.. He realises the ball has crossed the line. What then ? Mistakes have been made by referees for years, and its part and parcel of the game. Some go for you. Some clearly dont.. I see no reason why theres a need to change it, and more importantly, there is no possible way to change it without totally changing hte rules of hte game.