So what did I do? I googled "kid home activities". I found that crafts and kitchen science experiments worked the best with them.
Goop: Cornstarch, baking soda, and water make for a pretty cool substance that feels firm to the touch but will ooze out between your fingers. I hadn't done this since I was probably 10.
The big lesson? Idle time = trouble. Case in point: while writing this blog post this morning, I neglected to give the twins a focused activity and they went nutso. We had about 8 time outs because of hitting, scratching, spitting, and throwing. How do all those moms out there do it?