Microphones like in rugby is a superb shout. This, plus goal-line technology and a video referee is all that would ever be needed. We already have one of them (goal-line tech), microphones would take no time away from the game and prevent referees from talking favourable with any particular side, so it's really just the solution regarding a video referee that needs to be made.
If that stuff was in place, we'd have won at Chelsea, at least got to extra time against City but more likely gone through, and at least got a draw against Swansea.
Instead we have a point, a bitter cup defeat and yet another woeful home abomination.
If the referees would have microphones, there would be no/much less hounding of referees, no more Steven Gerrards encouraging the referee to change from a yellow to a red card, no more Guus Hiddink having a conversation about how many extra minutes he should add on, etc.
I think things such as handball calls would essentially remain at the discretion of the on-field referee, so could easily still be influenced ("I believe his arm was in an unnatural position" or "I felt he moved his arm towards the ball") - I believe the on-field referee will always be able to cheat and be affected by outside influences/money.