How do I run more than one city simultaneously?

I recently asked this question regarding if it's possible to run SimCity in the background. (In retrospect, this was a stupid question because if I had spent a moment to play with it myself I would have realized the answer was an obvious "Yes", but that's besides the point.) Now that I know the answer is yes, I am interested if it is possible to run two instances of SimCity simultaneously. For example, it would be nice to have one 'stable' city running in the background accumulating wealth with me actually playing a developing city in the foreground. As it stands now, if I just want to pass time in one city to earn some effortless cash, I can't actually play the game (unless you count staring at the screen doing nothing but watching a number increase as "playing").

I've tried the obvious things: Origin won't let you click the "Play" button while the game is running, and simply double-clicking the .exe file itself just brings up the current window. So then, is there a way to run multiple instances of SimCity simultaneously on the same computer so as be able to play more than one city simultaneously?

I think the simple answer is that you can only play two cities at the same time if you have two copies of SimCity on two different Origin accounts. Given that you can play in a region with other human players, I'd imagine that Maxis would have considered it to be giving an unfair advantage to some players if they were allowed to run multiple cities at the same time.

The better solution, although maybe not what you'd prefer, would be to play in a 'sandbox' region so that you can gain money through (developer-sanctioned) cheats.