Oh ...my... IPhone

Two days ago I got an IPhone. My kids are, well, quite happy about Angry Birds. I am quite happy about Angry Birds (and so is my husband but don't tell him because he refuses to admit he likes anything "Apple"). I can feel the inner struggle begin, though - how much can the kids play with my phone? August woke up yesterday, after knowing the IPhone for only six hours of his entire life, and the FIRST WORDS out of his mouth were "Mommy, where's your white phone?" Oscar, almost 6 years old now, played for at least 45 minutes and could have played much longer if we didn't insist he go to bed because it was 9:00. It's also the third day of November which means Halloween just happened. I loosened up and let the kids go buck wild with their candy. So, do I let them go buck wild with the IPhone? What to do...