If you're going to have a bet today, and let's face it, most people do (it's like the grand national), then make sure you're actually getting some decent value.
At the least go to somewhere like OddsChecker and get the best price, but really you need to be combining BetFair with some sign up or value offers from the other bookmakers.
Plenty of moneyback specials and value bets around as well. Great day to be a matched better, great day to be a football fan. Love the magic of the cup.
For what it's worth, I think it's Arsenal's name that's going on the cup. Like to see both teams score if possible, just so everyone has something to cheer at some point.