There's been plenty of talk during this World Cup about FIFA's reluctance to implement some sort of instant replay. While I am a big fan of instant replay in sports, I understand FIFA's reluctance. Whether it actually is a technology issue or not, the sport has always been one of continuous flow (see my post about continuous and discrete sports) and replay might take away from that.
That doesn't mean there aren't other solutions. In trading, most US exchanges have a "clearly erroneous transaction" policy. As with most US laws and regulations, the idea is sound but the execution is flawed. With regards to soccer, one can implement it by having an extra official watch a live broadcast with multiple angles, and only stop play if there was a clearly erroneous call. Something that could be identified in real time (no need for slow-motion replay). Perhaps only to help for something that is "line-oriented" like the England non-goal the other day.
If they really, really, really don't want to use technology, that's fine too. Have 5 officials. Whether it be two extra line judges or any other configuration, it certainly can't hurt. Three officials can barely manage an NBA game, let alone a game with a field that big and that many players. Sure they do it for rugby, but isn't futbol/soccer supposed to be the world's sport that's bigger than everything else?