I've got a plan, and I'm not afraid to use it!
This is what I've got planned - thanks Kate for reminding me about FlyLady! I need to remember to buy a timer, but after that, this whole room-cleaning business shouldn't be so bad. My plan is this: Give the kids five minutes to pick up all of any one particular kind of toy. We'll play "Beat the Beep" (stolen directly from a FlyBaby) or some such game to do it. "Ok, by the time the timer beeps, you guys are gonna have all of the cars picked up! Go!" By breaking their rooms down into more managable tasks, maybe this will take the pressure off of them, and maybe I won't get as stressed out.