In my last campaign we had a "Don't wake the Giant" scenario. We followed some of those rules listed above, but since it was a big multi-player battle, we devised the following rule. At the beginning of each player's turn, we would dice off for control of the giant for that turn, HOWEVER if any of your models were in close combat with the giant, you could not participate in the roll. Also, no player could have control of the giant for more than one turn. It gave the impression that the giant was confused and blundering around as it faced off against the numerous warbands. It seemed to work pretty well.