www.logiccircuit.org

I got to thinking about it after I posted the question, and I suddenly realized that using a JK-FF where J is tied to "D In" and K is tied through an inverter to "D in" might do the trick. I'll have to test it.

Does anyone have a D-Flip flop? I didn't see one in the software. D Flip Flops are good for making algorithmic state machines, which, when used with a ROM, can be very useful devices for controlling things.