I was playing Runescape the other day (good game), and I was thinking about the multiple accounts problem.
Part of how the cut back on fake accounts is that they don't allow transferring of items ("trading," as they call it) unless both parties are logged on. It seems simple, but it does crack down on things. Part of the problem with our system is that you can make bank transfers anytime of anyday to anyone.
The other part of how the cut back is by simply not allowing multiple accounts to be logged in from the same IP. Obviously, this makes it rather difficult to send items to a second account.
So, we can apply this quite well in this game, I think. The most effective part would be not allowing multiple IP's to be logged in simultaneously. I know there are those of you who are on the same router in your office, etc., but we have to think for the good of the game. Fake accounts must be stopped, and while our currents methods may work somewhat, but they're not 100% there, and they're a pain to boot.
And the other part: both parties must be logged on to perform bank transactions. This should REALLY kill transferring items between multiple accounts, when combined with the above rule. I know it'll be a pretty big bother, but I think it's workable.