I'm always looking for a way to get my son to help me around the house. I got this great idea from FamilyFun. I had to adapt it for my son's age, but it's been working great. First, you need to find some fake dollars or certificates. I just picked up some play cash from my local dollar store. You can also surf the web to find things to print, like Daddy Dollars (which is what the FamilyFun people used--just a dollar with Dad's picture in the middle instead of George Washington). Our system is very unsophisticated. Every time my son does a job I ask him to do he gets a dollar (or two if it's hard). Every time he wants to watch a movie, watch cartoons, play the computer, play video games, etc. he has to give me a dollar back. This way you're encouraging help (without yelling!) and also managing their time with electronics. I love it!
*If you want to read the article from FamilyFun, it was called "Daddy Dollars"