I used cheap transmitter & receiver circuit boards from an RC toy car set that I bought at Radio Shack. It has four outputs, or cues, as they are known in the firework business. I also made my own electric igniter's from Christmas light bulbs.
I use it to safely ignite my fireworks at parties. It's really nice not to have to run away after lighting a firework with a lighter. And it lets the kids have a (safe) chance to light their own!
Here's a link to my project:
4 Ch Wireless Firework Igniter System
And how to make electric igniter's from Christmas light bulbs:
Electronic Igniters