I've been playing with 7-segment LEDs over the past couple of days, starting with the LED and a '4543 BCD decoder, then adding a counter, a debouncer for the switch that drove the counter, and eventually a timer to make it count by itself. The writeup is here.
I feel compelled to prepare these elaborate writeups so I don't feel quite so bad when I tear the circuit down. It's not like woodworking (alas), where you end up with something to keep when you're done. Instead, build a circuit, take it apart, build another one, take it apart, and so on. Well, I'll keep some circuits. This just wasn't one of them.