I don't think we should - it slows the game down way too much, and it would be overused, in sports such as Cricket it's OK, its not a particularly fast sport and the umpire only calls on the 3rd upmire when really necessary, it's also a lot more difficult (from what i've seen) to make these decisions without it, par example the "snickometer" which the TV crews certainly use to see if the ball and bat made contact.. also in Rugby, it's only used to decide a difficult decision whether or not to award a try, when there are twelve 18 stone beasts lying on top of one another + there is a lot more respect in that game. I think goal line technology is, however a good idea, so perhaps there can be a few moments where 4th official can say something in ref's ear.. also i don't think that extra linesman, like in the Europa league are making the slightest bit of positive difference.. I do however believe it is good for the game if referees, like Howard Webb did the other day, come out and speak to TV afterwards about their decision and why they made it, **** perhaps they'll even admit they're wrong now and then!