My son's Boy Scout troop finishes every year with a group rocket launching party. I wanted to build a rocket launcher with a little more flair than the boring ones Estes sells. This project is designed to look way more impressive than it actually is. For all the switches, wires, blinking lights, and proto-perf all this really does is control a mechanical relay with an ATTiny. What really sells it though is the big "missile launch" switch from SparkFun. The red cover, arming LED, and solid "clunk" when activated all screams "we're about to launch a rocket!"
One little twist I added for fun was a Tamura hall effect current sensor. Once the ignition signal is sent the ATTiny's ADC monitors the current sensor to diagnose misfires. If no current flowed to the e-match the display sequence finishes with 'L' indicating an electrical problem. If adequate current to light the e-match was detected the display sequence ends with '0' (okay). If you see '0' and the rocket didn't ignite then you have a dud.
You can take a look at the Arduino sketch for the ATTiny on GitHub.